Lost Overdrive

robotennis61wrote: i am going to tackle this myself when i get my new scanner in sometime mon or tue....

who is this guy ? and how big does he think his balls are?

Is it throwing a code?
Sounds like Torque Converter Clutch failure, it will shut out 4th gear sticking you in "limp home" mode until you shut the car down once.

Can happen for a few reasons, usually it will pop up on steep inclines when you "goose it", cause the TCC can't hold the horsepower thats going into it VS. the RPM(happens on uphills and when very hot where the 4t60e tries to downshift, which triggers the "limp home" ) ... so yeah, like was said, could be the solenoid...or if its just done it the once, a trans cooler has been known to keep it from happening again for awhile(if you're short on funds)

good idea karma. i have one in the garage and ill instal it as soon as i buy a tube flareing tool.........

It sounds like Karma's explanation is right on - if it's a fact that TC clutch failure will cause a limp home with no 4th gear. Based on robo's description, he had no 4th gear - so this is plausible.

However, a TCC solenoid that fails to engage the TC will not cause a limp home or loss of 4th gear, at least not on a Series II engine. You simply get a DTC code for the solenoid being stuck-on, TC does not lock up, and the engine will run in 4th gear (not what happened to robo - he lost 4th gear).

Maybe Series I behavior is different? Or, maybe TCC failure causes a different response than a solenoid that is stuck.

As a side note, I find it peculiar that this problem occurred only a week after the Lucas stuff was added. Some will say that another 'brand X' product works better, and many more argue the Lucas works better. I say put anything other than transmission fluid in the transmission, you're asking for trouble.

At the RPM's and Speed he referred to I was thinking it was just a failure of the TCC to lock up.
I remember mine acting the same way and at about the same RPM's and Speeds, so that's why I mentioned TCC.
I did not think he couldn't obtain 4th gear.?

Usually when you get into the mid-3k RPM range, you're in 3rd gear, although he was moving pretty fast.

Do we know if the gear/drive ratios are the same for Series I and Series II transmissions?

This is example of where the TC vs. OD terminologies can cause confusion. "OD" means 4th gear. "TC" means torque converter (lock-up). But I can understand why people call it overdrive, because you need TC lock-up to achieve true overdrive.

At the moment I'm thinking that the first transmission fluid change ought to involve dropping the pan (to get the manufacturing metal shaving crud out) and switching to a full synthetic version of the correct fluid (to prevent future varnishing) and most likely ought to be done according to the 'severe' use schedule (if you read the fine print, most trans use for city/subutban driving turns out to be 'severe').

I suspect that most but not all trans additives are fluid modifiers made to compensate for deferred maintenance by messing with fluid viscosity and lubricity.

I also suspect that GM transmissions, good as they are, may have some manufacturing issues. This is only based on the observation that good rebuilds of these trannies have run significanly longer than the original builds. Which indicates that some design and engineering decisions were probably not made with life-of-the-vehicle value to the customers in mind. I hope GM has incorporated some of their service experience and a peppering of aftermarket know-how into improving Job #1 of the tranny builds in their current cars.

Albertj

I think I'll put a drain plug in my oil pan and change to Dexron VI soon.
I know i won't get all the fluid out but if i do it periodically I'll probably be better off.

AA wrote:

Do we know if the gear/drive ratios are the same for Series I and Series II transmissions?

1995 4t60e:

Model Code:
5BFW

Description:
3800 Supercharged G Body (6-bolt side cover)

Differential
Ratio:
*3.29

Sprocket
Ratio:
37/33

Overall
Ratio:
2.93

VSS
Reluctor:
31

Stall
Speed:
1897

AA wrote:

Usually when you get into the mid-3k RPM range, you're in 3rd gear, although he was moving pretty fast.

This is example of where the TC vs. OD terminologies can cause confusion. "OD" means 4th gear. "TC" means torque converter (lock-up). But I can understand why people call it overdrive, because you need TC lock-up to achieve true overdrive.

I was thinking of only a TCC problem as well... I cruise at 75 with 2 grand on the tach. If I tap the brake lights & release the TCC, I'll pick up almost 500 rpm. He was going 10+ MPH faster, so I could easily believe 3,000+ on the tach with no clutch, but still in OD.

Just to clarify for everyone, the terms OD & 4th are used interchangeably in OUR transmissions. Overdrive means a gear ratio numerically lower than 1:1, which is called Direct drive. In our cars, 3rd (or Drive) is 1:1 and Overdrive is about 0.7:1... In a 5 or 6 speed transmission, 4th might be Direct, and 5th & 6th are progressively taller ratio Overdrives. And of course, as AA said, the Torque Converter Clutch is just that, an independent device in the converter that does it's own thing in both 3rd and 4th gears.

Rickw wrote:

I think I'll put a drain plug in my oil pan and change to Dexron VI soon.
I know i won't get all the fluid out but if i do it periodically I'll probably be better off.

That's a big 10-4 on the plug, first thing I do when I change tranny fluid on a new car.

Eldo wrote:

That's a big 10-4 on the plug, first thing I do when I change tranny fluid on a new car.

Is there a Dorman Kit or something that includes the Plug and a Nut that can be tacked welded to the inside of the pan.
I would think the pan material is too thin to just drill a hole and screw a plug in: yes / no ???

Rickw wrote:

Eldo wrote:

That's a big 10-4 on the plug, first thing I do when I change tranny fluid on a new car.

Is there a Dorman Kit or something that includes the Plug and a Nut that can be tacked welded to the inside of the pan.
I would think the pan material is too thin to just drill a hole and screw a plug in: yes / no ???

It may very well have been Dorman...
It's a bolt within a bolt. You cut a hole with something like a 1" hole saw, put the outer bolt in and tighten it down with a nut and a plastic washer/seal on the inside of the pan, and the 'plug' bolt screws into the first bolt.

Rickw wrote:

I think I'll put a drain plug in my oil pan and change to Dexron VI soon.
I know i won't get all the fluid out but if i do it periodically I'll probably be better off.

Hey Rick. You got me thinking about the tranny pan drain.

I am not sure I would bother installing the drain plug in the tranny pan, if only because I'm not sure you'd get the metal bits off the magnet in there just draining the fluid thru a hole and you probably want to get at the filter anyway.

interesting idea though...

Albertj

How about removing the magnet from the pan and using a magnetic plug.
To me, that would work. And like others have said at a predetermined amount of miles replace the filter and gasket along with the partial fluid change.
Certainly would make dropping the pan easier if you could drain it first.
Would eliminate the need for a flush and I thought that's what this was all about.?
Even though the title to the Topic doesn't say so. Partial Hijack, I guess.

I still miss the Torque Converters with drain plugs. That's going way back.

YEAH this is a hijack...

Hmmm...

if you're still going to drop the pan for filter changes I would nto worry much about magnet. except maybe to stick a more powerful one in there. And it would make dropping the pan easier.

You know, if you could stick a cartridge filter with a magnetic trap on the line to the tranny cooler maybe you could then put on a hollow trans filter in the pan, and not really have to drop the pan except for initial 1 or 2 servicings - could leave a magnet down there but with a trap by the cartridge I'm not sure how many shavings you'd see. From an engineering point of view I probably would not bother doing this (filter changes are not frequent) but as an enthusiast it's interesting.

Albertj

Rick, I got a magnetic drain plug kit for my pan at Napa. I just asked the guy and he pulled it from behind the counter, I have no idea what the number was and it was about $8. It was the larger bolt, two plastic (sealing) washers, large nut, and a small bolt that went inside.

deekster_caddy wrote:

Rick, I got a magnetic drain plug kit for my pan at Napa. I just asked the guy and he pulled it from behind the counter, I have no idea what the number was and it was about $8. It was the larger bolt, two plastic (sealing) washers, large nut, and a small bolt that went inside.

BINGO!

$6.25 + at Amazon

Link

for the universal magnetic drain plug kit.

Filter kit (with what looks like the ubiquitous PH16)

http://www.amazon.com/80277-Universal-Remote-Transmission-Filter/dp/B000CIKJMY/ref=pd_sbs_auto_2


Albertj

i have one instaled on my tranny pan and it works good. when i changed fluid and filter i noticed that the plug nut was a little loose but no leak.

robotennis61 wrote:

i have one instaled on my tranny pan and it works good. when i changed fluid and filter i noticed that the plug nut was a little loose but no leak.

Yes, I forgot to add to my original post about aftermarket plugs that even when they are tight and leak-free, the large bolt will rotate in the pan... You generally need to hold it with a crescent wrench when removing the plug.

I actually have had my transmisson lose overdive twice in the last year. I had no idea what cause the problem but when I let the car cool off and sit everything was fine.

maggot wrote:

I actually have had my transmisson lose overdive twice in the last year. I had no idea what cause the problem but when I let the car cool off and sit everything was fine.

I've had my tranny go into 'hot mode', where it modifies shift & TCC behavior, 2 or 3 times... when the ambient temperature was in the 60's!

I guess we need another acronym: IAM - It's A Mystery

Eldo wrote:

blackrose613 wrote:

spedo is fine. other than no OD and no cruise, the car is actually running well now.

things recently replaced: ignition switch and neutral safety switch.

could a TPS really cause this?

I'd like to think that anything that causes 2 problems would set a code and light the MIL...

But if not, now that you mention it, something I could see messing up OD and Cruise would be the "neutral safety switch". On these transmissions, it's much more than that, it tells the PCM exactly what gear the shift lever is in... If it was installed incorrectly, I think it could cause a Cruise Inhibit and prevent OD. Again, though, why no light? Do you have a scanner?

No MIL has been set. I dont have a scanner. I bought a actron CP9145 but it does not work so I am looking for a new one. I am going to try to hook my laptop to the car and see if any codes at all are present.
I had a shop replace the NSS so I think it is going to go back to them. I had OD and cruise before it went in to have the NSS and Ign switch replaced.