Write-Up: Transmission Cooler Install

First time i have put an EDIT at the top of a post, but I admit i missed the last few post's. So some of what i have said, if not all, is redundant.

One thing that Aaron did point out a while back was that our Transmissions put out more than the average operating pressure.
I believe it was in the high 90's (psi).
Now with that being a fact, as measured, then I agree with a lot of protection to compensate for high outlet pressures.
That's why i don't just cut the lines and put a barbed splice in the line, like i have done on older American V8's.
I learned quite a bit by reading about the pressure's and temp's that our Transmissions encounter during normal operation.
Somewhat different than i was used to.

But what I will ask, is the above (and now below) clamps you had a pic of equal to the hose clamps that are crimped on, like a CV Boot only meant for 3/8" diameter hose.
I have those in stock and the proper crimping pliers.
Actually the clamps i have are for 11/32" hose, which is what i would use on the Auto Trans line. It is the same hose I use on certain applications of motorcycles.
Just a tad tighter than 3/8" on a 3/8" nipple with crimped clamps. Or would you recommend just using the screw type clamp instead of the crimped type.

BrianEsser wrote:

Fuel injection clamps will have no issue with those pressures.

If you want to make sure, simply put a slight flare on the end of the steel line, it will hold the hose and prevent it from slipping off if clamped.

These are the clamps you want, not worm gear style.

Brian,
I assume these are available at all Auto Parts Stores.
The only reason i do not know this is i don't work in the automotive industry and a lot has past me by in last several years from being out of commission.
Thanks for your input on this site, it is very helpful.
I'll grab a handful of these and see how they work and I'll put a slight single flare or a bubble flare near the end of the steel tube before putting the hose on and clamping it.

Yep, every parts store should carry these. They are designed specifically for high pressure applications (IE 100 PSI fuel systems). They completely encase and wrap around the hose and act much like a crimp, as compared to the much weaker worm clamp which most people are thinking of when I say use clamps.

I know for a FACT they are quite capable if installed correctly of holding 100+ PSI as we have used them for on some applications. I also use them and only that style on my shop air lines, which are usually over 100 psi and get tossed around and abused.

What I do with such lines is to put a flare into the line to act a barb, then double clamp with fuel injection clamps, NOT radiator hose clamps (worm clamps). They act as a crimp and prevent the hose from clipping off past the crimp. I have yet to see this method fail.

Quote :

I don't mean to argue with you, and I am most certainly not calling you a liar, it's just real world experience versus internet stories tells me otherwise...

Yes, I can tell you didn't read the thread - the bulletins from INTENSE and ZZP were copied and pasted directly from their websites. I had no opportunity to make anything up. It's their exact words from the tech bulletins. And it's not just their opinion - it's at least one real-world case of hose/clamp failure resulting in a bad situation. They won't install coolers because they're afraid of the liability in doing so. They can build and install a transmission, modify a motor from the inside out, install aftermarket braking components, but they will not install a trans cooler.

Brian, what you are saying, as I am reading it, is there is a real danger in using gear-style clamps to install trans coolers. Since virtually every cooler kit uses the gear-style micro clamps (not the fuel injection clamps), the danger seems very real. So we now have a 3rd professional opinion informing us of special instructions that must be followed to avoid disaster after a cooler install. That's really interesting to me.

Btw, all adapters and tube ends in the kit I bought had barbs or flares to secure the clamped hose from slipping off, so I'm not that worried about it happening. I'm also not worried about the gear clamp failing, because mine were torqued correctly. Since the hose has been upgraded to high-end, it's not going to crack or burst, and that lets me sleep easier at night. Unless one of my gear clamps starts to leak, I'm likely not going to switch them out - but if they do, I'll try the clamps you suggest.

What I am saying is, YES, there is a danger in using WORM CLAMPS on our transmissions, not the fuel injection clamps. It's not as if these transmissions run at some insane pressure, 96 PSI is higher than most transmissions, but well within a workable range. As for most if not all transmission cooler kits coming with worm clamps, maybe because most of them end up on older applications running lower pressures.

i would NOT try to clamp GM rubber transmission line with clamps, it's simply not soft enough and it will not hold. I would at the minimum upgrade all the rubber lines. Go compare GM's tranny hose to most modern rubber lines, the stuff is thick and massive in comparison, yet the aftermarket stuff is rated for over two or three times the operating pressures (if not more) than it will ever see in service, and the clamps work quite well up to 150PSI pressures.

I would venture to say ZZP and intense won't install coolers due to the reason I stated earlier about the GM line being too thick and bulky to clamp properly. Sorry, but until someone can show me a concrete reason why clamps/hose that is rated and KNOWN to work at much higher operating pressures than our cars could ever throw at them would not work. I will hold my opinion.

Now, with that being said, I am positive there have been nightmare horror stories, then again, you can say that about pretty much anything we do to cars when someone who doesn't know what they are doing attempts to make a modification or repair, and that includes people who should know better.

Quote :

Now, with that being said, I am positive there have been nightmare horror stories, then again, you can say that about pretty much anything we do to cars when someone who doesn't know what they are doing attempts to make a modification or repair, and that includes people who should know better.

I am sort of counting on this being the case. For years I believed our cars didn't need transmission coolers because the big 3800 vendors said so. I also believed there was too much risk because of the potential for failure, also because of 3800 vendor info.

My first transmission failed after 150k miles, because the TCC lock-up solenoid got stuck and wouldn't lock-up the TC. This worked fine for a few months, but then once on a 400 mile drive I learned the hard way that heat can break our transmissions, despite what the vendors say. Without lock-up, the sustained fluid coupling in 4th gear caused my transmission to heat up so much, it burned the fluid black and turned the TC blue. That in turn cascaded into a mechanical failure.

After that, I noticed that anytime you are out of TC lock-up, the transmission will heat up, slowly but surely. On a long trip, this can become a problem. This doesn't work well with my set-up, as my TCC lock-up program is set to be off with very little throttle application (a driving preference). Also, for anyone who wants to take a long, spirited sprint through steep hills with lots of throttle, if you check your trans temps afterward, it's obvious the radiator can't keep up. It's not hard to hit 250ºF in the summer. Working the trans very hard can even raise your coolant temps higher than normal.

So, now that my rebuilt transmission is passing 50k miles, I'm looking for ways to take better care of it without compromising my driving habits. A trans cooler seemed to be the best route. However, I don't want to dismiss the things I read from ZZP and INTENSE, and RegalGS. I know it's easy to assume those incidents of failure were because the installers were incompetent, but we have to realize that these things happened to people just like us - performance enthusiasts who thought they knew enough to do the job right. I don't want to be one of the case studies, which is why I've made such an effort to find out exactly why these things happen.

Pressure is one of the factors. Most automatic transmissions (according to a JEGS rep) operate closer to 45 PSI. Even if the hose is rated much higher, it's logical to assume ours will fail sooner than the rest, when something does go wrong.

This has been discussed throughout this thread: double clamping is suspected to cause a shearing of rubber hose because of stresses created between the clamps, which can cause a crack to form. It is for this reason many cooler installation instructions strictly advise against double clamping. This is what makes me feel that the hose (even rated at high pressures) is the weak part of the system, when combined with sharp, steel clamps. I've formed the opinion that using a braided covering over the hose will help distribute and attenuate the forces that cause this, lessening the risk of cracking and ultimate failure.

Here is some info about the hose I use.

http://www.goodyearep.eu/productsdetail.aspx?id=10534

It has a working pressure of 250 PSI and a burst pressure of 1000 PSI. No way 100PSI is even stressing this stuff, so that leaves the clamps, I can see the idea behind the theory about double clamping. I've never saw the need so long as you are using proper barb fittings, and placing them in the proper location, which is near the end of the hose. People tend to make the mistake of clamping further down the hose, instead of towards the end, which can cause distortion and reduce clamping force, leading to blow offs as well.

I clamped closer to the barb. There's really no room to clamp farther away on some of the connections - the fitting tube just isn't long enough.

I found a manufacturer in the UK who claims a hydraulic pressure spec of 203 PSI on their smaller worm-gear clamps: http://www.jubileeclips.co.uk/products-clips-standard.aspx

UPDATE: took a 260 mile round trip, no towing this time. On the first 130 mile leg, it was 80ºF and sunny, dry. I started out about 80 mph, but soon was overtaken by a white 2-door G35 leading a pack of cars at between 85-95 mph. I entered the group and soon caught up to the front. The Infinity and I left the group, trading lead spots for about 90 miles. The trip consisted of a lot of irregular driving, speeding up & slowing down, plenty of WOT as there were a lot of cars on the road. We would wait for it to open up, then sprint to the next clog of traffic, then wait again.

Max trans fluid temp was 199ºF after pushing the car hard at WOT up a 2 mile grade near the end of the trip (G35 was right beside, we were flirting with a race, but it didn't happen); it would always settle back down quickly (within 5 mins) after hard abuse. I have never been able to reach 200ºF since the cooler was installed. In case anyone is wondering, the ability of the radiator to cool the engine does not appear compromised by the placement of the trans cooler in front. Engine temps are consistently near the 180-185ºF range even on hot days.

I inspected the cooler fins after more than 1000 miles - no serious dents, but a few bugs that met their end. There were some very minor bends in some of the fins, which are easily corrected with needle nose pliers. The open location makes it very easy to access.

i'm curious what the temps will be like in stop -n-go traffic on a 100* day. My temps have to be hot as hell, and i've been considering getting one of these but i'm also toying with a S2 IC and i'm not sure i would have the room in front for everything and still have air movement to the main radiator.

Haven't had a 100ºF day here yet, but on a 78ºF day I was seeing about 178ºF trans fluid temps sitting idle. I'd guess with hard stop and go driving, it might rise to 185ºF or so not much more. This cooler works even better when you're slow & go, compared to constant high speed operation. Driving 80 mph+ is what really heats up the trans.

AA wrote:

Without lock-up, the sustained fluid coupling in 4th gear caused my transmission to heat up so much, it burned the fluid black and turned the TC blue. That in turn cascaded into a mechanical failure.

After that, I noticed that anytime you are out of TC lock-up, the transmission will heat up, slowly but surely. On a long trip, this can become a problem. .

This is a very important lesson...

The average person wouldn't have noticed it, but when I switched from a car with a normal TC, to one with a TC with a lockup clutch, I could tell that they had significantly raised the stall speed of the converter. Basically, because they now had the TCC to fall back on for cruising conditions, the Rivi's TC is much 'slipperier' than they used to be - which increases performance at lower speeds. However, when the clutch fails, you end up with a "drag racing converter" for normal, sustained driving... As AA found out, this is a recipe for uncontrollable heat buildup.

And I should clarify, with this cooler you can control that heat build-up when the TC doesn't lock up in 4th gear during a long cruise. As Eldo said, this would be a recipe for thermal runaway using the OEM cooler, but it's not with the Tru-Cool MAX installed, even when towing a load. The reason I know this, my TC lock-up program is so easily disabled with mild throttle application that when I tow it actually isn't engaged most of the time. I've driven hundreds of continuous miles with no problems keeping the temps below 200ºF.

I'll come out with it now - part of the reason for me buying this cooler is that I don't know how much life I have left on my TC clutch. It's been acting odd for a long, long time, throwing codes now and then, and at times it seems the PCM will disable the feature, so I have decided to use it sparingly, and I want to be prepared when it finally gives up the ghost. Fuel economy will suffer some, but at least I won't need a new transmission.

is your TC going due to wear and tear/age or is it related to your trans settings and driving habbits?

There are a lot of factors to consider:

1) my TCC program settings - having the clutch come on off more frequently could wear the clutch more, although it's been in use for ~100k miles. However, this also means less torque stress on the clutch, so could make it last longer.

2) my trans was rebuilt, and I'm not sure if AAMCO used the best TCC clutch materials. It's been 50k miles since the rebuild. It's possible there are some parts that didn't get replaced.

3) I have pulled my trailer loaded in OD with TC lock-up. Referring back to #1, I think that extra load puts significantly more strain on the TC clutch.

4) As I posted in another thread (Link) I've recently had lots of P0716/P0717 codes, usually occurring consistently with loss of TCC lock-up. Otherwise the trans works fine.

5) I've driven the car hard in hot temps without a trans cooler for most of the car's 200k+ mile life. I am late in the game installing the Tru-Cool MAX.

6) Although the trans was rebuilt, there are some parts in there with over 200k miles, so age should be considered.

Aamco probably used a cheap converter, so who knows what friction material is in it.

BrianEsser wrote:

Aamco probably used a cheap converter, so who knows what friction material is in it.

And from what I've been told by friend who owns a tranny shop, you'd be shocked to see what a thin little "piece of paper" the clutch is in the first place...

Exactly. There are many factors that come into play, second to clutch material itself is the size of the shell surface. Which with cheap and some aftermarket converters is a joke. TCI is a fine example of cheap shells.

I remember the AAMCO guy saying the same exact thing about the clutch when we we talked about it a couple years ago, so I believe you when you say it's very thin.

Aaron,
Since the ambient temp's have become much hotter, I was wondering if you have an update on your trans fluid temp's with the new trans cooler.

I am thinking i might be able to accomplish this mod later this month or next month prior to a Hidden Hitch install.

This month is definitely the LIM gasket change for PM purposes. And if i can swing it I'll be ordering the cooler and thermostat / bypass unit.

I have forgotten, did you purchase and install the thermostat for the system.?

Thanks for any input you may have on this.
Rick

Ambient temps were in the mid 90s-100ºF over the past week. Most of the time my trans temps stay near 185-190ºF, since that's what my engine coolant temps are; the cooler is plumbed through the OEM radiator. It is very difficult to push the trans temps over 190ºF in normal driving, even on very hot days. And this is with my TCC clutch disabled - I've decided I don't need it anymore. I like the added response of plain 3rd & 4th gear, and the hit to fuel economy is only slight.

There have been 3 times this summer when I've tested the cooler in extreme situations:

1) towing a roughly 1000 lb load over 200 miles through rolling hills.

2) driving near constant 90-95 mph for over 80 miles straight.

3) autocrossing, eight consecutive 50 sec runs in 1st gear at between 3-6k RPM (95ºF ambient).

These were all on hot afternoons, and never was I able to push trans temps over 200ºF, except for the autocrossing. Max was 198º, and this quickly dropped as speed/RPM dropped to normal levels. The Tru-cool MAX cooler sheds heat very fast. It has given me the impression that my trans is bulletproof, at least thermally.

I did use the thermostat. I advise you install it, too if you'll be driving the car year round.

Very cool, I'll be buying the same package then. That's what I needed to hear.

Derek has disabled my 3rd gear TCC engagement for me about 6 or so months ago and I much prefer it this way based on the type of driving I do in the country back roads.
Now I want to delay the 4th gear engagement to at least 50 mph because it seems I'm always right at the speed for 4 th gear engagement while cruising these roads, it happens at about 42 to 44 mph and then goes into 4th gear TCC engagement soon after or overdrive, depending on what you want to call it.
Now it feels like it's lugging at that speed (42-45 mph) so I find myself manually putting into 3rd to cruise my normal driving routine.
But, being a dumbass and old and forgetful, I have actually found myself on the highway still in 3rd gear and can't hear the higher rev's. It takes a while before I glance at the Tach and realize I'm still in 3rd. The last time it happened I was already on the highway for about a 1/2 hour in 3rd running at a much higher RPM than I should be.
I need to have the Trans reprogrammed again for 4th soon before I cause some damage.
Then i can just leave the lever in the 4th gear position and not worry about my forgetfulness and lack of hearing.

Derek, if you should read this, PM, Email or call me about getting together again for a short session. And I'll be able to get a look at the "New" car.
I have British car blood in me, maybe i can be of some assistance to you for a change.

Heres some pics of my install of the same package:
(Hey! The bypass is made in Canada! Cool! It was exported, I bought from an American company, and re-imported...)


Since I had some weeping connections from the metal lines to the stock rubber I opted to cut, bubble flare, and clamp to the metal lines.

These guys are in an awkward position to cut, but a tiny tube cutter does the trick:


Lines cut an ready for flaring:


Now, I didn't know which was the send from the transmission on the 4t60e, so I opted to cut and check which it came out. A simple idea, but it was rather funny how it worked out. I had my dad come out an watch which line it came from. The goal was to just turn the engine over once. Well, there was a communication breakdown, and he though he would just hold his finger over the lines to "feel" the pressure. yep. So the first turnover and off, nothing happened. So the second time I let it start. And instantly heard "STOP! STOP!". Which i did. I looked past the hood to see dad blinking and covered head to toe in transmission fluid. I was laughing, and he just said "I know which one it comes out from."

Anyway, send is the one with the bend closer to the trans case, or the shorter one in this picture:


And bypass hooked up:


Mounting:


You can see a slight mistake on the left for mounting, but I drilled a new hold and all is well. This thing is rock solid.




I went with the fancy fuel injection clamps with the little bolt through them. Works like a charm. Trans usually sits at 185 in hot normal driving, and 190 when thrashing it. Considering it was normal to see 210-220+ before, this is a great mod for the hot little 4t60-e which has most of its failures related to heat.

Very clean, simple way to install the cooler - great job. Looks like you bypassed the OEM radiator cooler. And nice how you installed the bypass right off the transmission lines!

It should also be noted, then when going right off the stock metal lines, there is exactly enough hose supplied in the kit to get to the cooler and back again.

I finally replaced my lower radiator hose (and "factory installation stub"... ) and I simultaneously used Jason's wonderful writeup and photos on Page 1 [and the exact same cooler] to add a tranny cooler to my car. I just want to add a couple of updates...

Jason wrote:

Here is my writeup...
I used the Mr. Transmission kit which is sold at canadian tire.... The cooler I used was the medium one (7 1/4" x 11 x 3/4) and is a stacked plate design.

In the USA, this is the standard B&M stacked-plate-cooler kit, #70268, rated at 13,000 BTU's...

Quote :

Using the 4 supplied steel mounting brackets and the existing holes and screw, in the riviera I mounted the cooler. I mounted it towards the passenger side, inlet and outlet towards the bottom. I anchored the mounts to
a) the lower passenger side bolt of the radiator "X" brace.
b) the lower, driver side bolt of the brace in front center of the radiator. (This brace holds the hood latch assembly)
c) the lower bolt on the hood latch assembly itself. Using the drill, you will need to enlarge one of the holes on the steel mounting bracket to get this bolt through the bracket.
d) the top passenger side bolt that is right next to the airbag sensor assembly. I had to shape this last steel mount to have 2 90 degree bends it so that the cooler would lie flat. It is quite easy to shape and can easily be bent with your bare hands.

I would only add to this section that you should be careful about the location of your cooler relative to the grill that is going to be coming down when you close your hood... Jason used one of the cushion-pads between the cooler fins and the hood-latch brace, but I wanted to clear both this brace and the fiberglass 'swoop' on the passenger side... I will show with my (very bad) photos, that you can mount this cooler almost the same way as Jason llustrated, but if you let it get too far forward or too far to the passenger side (due to the curvature of the grillwork, you can have a VERY unhappy experience when you close your hood.


.

Quote :

I recommend fastening the cooler to the mounts by inserting the bolts so that the head of the bolt and lock washer (both supplied) are on the radiator side, and the nut (supplied) is on the bumper side. tightening them will be much easier.

I found that all but the lower-starboard cooler bolt could easily be mounted head-forward. This is also less visually obtrusive...

Quote :

Also remove the 2 bottom retainers of the passenger side inner fenderwell (also held in by plastic retainers). You'll probably need to pass your hand through there later on.
Place a catch pan under the passenger side radiator core and have the other one handy. The catchpans can be small because there is very little fluid that will leak out (much less than 1/4 quart)

Now that we've found out that the "return" fluid goes out the upper radiator trans-cooler fitting, things get a lot easier, and you don't have to worry about the fenderwell, the lower fitting, the air-dam/splash-guard, or even an ounce of fluid leaking out. In fact, being that the tranny cooler lines travel cross-ways below the radiator, the metal line that you have to tie into doesn't even need to be bent... The brackets holding it to the cross-bar let you swivel the top of the tube back enough to connect the adapter and rubber line from the new cooler, and not make contact with the pulleys or lower radiator hose.

Quote :

Connect the appropriate 3/8" adapter (supplied) into the radiator. The kit comes with 4 fittings (2x5/16" and 2x3/8"). You won't be needing the 5/16s.
MAKE SURE NOT TO DOUBLE HOSE CLAMP ANY CONNECTION POINT.

At least on my '97, it was the 5/16" fittings that fit (3/4" tubing wrench, I believe...)
Also, I DO agree about the double-clamps - From what I saw in my kit, the quadruple-barb fittings could practically hold the pressure by themselves... More importantly, except for the space right behind the hex-fitting, if you added another clamp, it would be pressing down on one of the sharp barbs, and probably cause the hose to cut through.

Quote :

I think i will paint the shiny metallic mounting brackets flat black (with tremclad rustproof paint) because you can see them when looking at the front of the car. In retrospect, I should have painted them before the installation.

Yes, as you can see (except for the shine on the drivers' side, top bracket) I first spent my time bending and drilling and cutting the brackets to fit, and then painted them while I was waiting to actually plumb the sucker in. )

And the path of the hoses up the passenger side...