96 na riv trans issues!!

hi all just picked up a 96 na riv with 107k not bad shape but the trans takes alot of rpm to shift into 3rd and od . i changed some vac lines seemed alittle better any other coments would be greatly appreciated! just neeed a new set of eyes on it! no codes eather. thanks!!

When was the trans fluid/filter last changed?

Have you checked fluid level and color?

Check the vacuum modulator. Look for transmission fluid on the vacuum side. Any fluid on the vacuum side indicates a leaky diaphragm. Test the unit with a vacuum pump to see if it holds vacuum. Make sure the modulator is receiving the proper manifold vacuum, and that the manifold vacuum is about 20" in Park, engine fully warm.

hi larry fluid is clean bought a new modulator need to check the vacuum thats if i can get the only key fob to work!!! last owner gave me no door keys!!! thanks for the responce

See if the dealer can help you out if you give them the VIN and document that you own the vehicle. FOBs are available on Ebay and you can program them yourself with the ignition key.

got the keys and fixed the fobs. i tried to check the vacuum and my guage is broke had to order a new one .i did change the modulator and it helped just have to adjust it! thanks lary

i did a trans fluid change have good vacuum at the manifold 1st to 2nd sift is good 2nd to 3rd i have to get it over 3000 rpm then it shifts. put two new adjustable vacuum modulators on it with no change any way its screwed in or out.what to do next? thanks

The next thing would be a Throttle Valve cable out of adjustment, or a governor problem.  I do not know enough about the 4T60 transmission(Is that what a 96 Riv has?)  If you own a 95-99 Riviera, a Factory Service Manual is not optional IMHO.

This Ebay auction is one book of a 2 book set, but it's cheap enough and this book has transaxle diagnosis,

http://www.ebay.com/itm/1996-BUICK-RIVIERA-AURORA-Service-REPAIR-Manual-ENGINE-ELECTRICAL-TRANSAXLE-/182380811077?hash=item2a76be5345:g:yMMAAOSw-0xYPjrx&vxp=mtr

Here's the 2 book set,

http://www.ebay.com/itm/1996-96-Oldsmobile-Aurora-Buick-Riviera-Service-Manual-Repair-Dealer-Dealership-/351766653149?hash=item51e6ed28dd:g:Ug0AAOSw-4BXa1BD&vxp=mtr

Here it is on CD ROM, if you prefer that,

http://www.ebay.com/itm/1996-Oldsmobile-Aurora-Buick-Riviera-Shop-Service-Repair-Manual-CD-Factory-OEM-/370782826644?hash=item565460f094:g:NnQAAOSwQYZWu880&vxp=mtr

thanks larry im going to need some reserch books to move forward

I wonder if, if you ran that riv long enough with the trans out of adjustment, if the PCM has put the parameters (shift points, line pressures, etc) at their limits. You might need a Tech II to check. Anyone else have any insights on this?

albertj wrote:

I wonder if, if you ran that riv long enough with the trans out of adjustment, if the PCM has put the parameters (shift points, line pressures, etc) at their limits.  You might need a Tech II to check.  Anyone else have any insights on this?

I'm not sure which transmission was standard on the 96 Riviera. Was it the 4T60 or 4T60E. How much electronic control was there?

Im thinking they are 4t60e's did some reading and maybe a speed sensor. the speedo works fine! need more info

LARRY70GS wrote:

albertj wrote:

I wonder if, if you ran that riv long enough with the trans out of adjustment, if the PCM has put the parameters (shift points, line pressures, etc) at their limits.  You might need a Tech II to check.  Anyone else have any insights on this?

I'm not sure which transmission was standard on the 96 Riviera.  Was it the 4T60 or 4T60E.  How much electronic control was there?

If I remember my Riv history right (good luck with that) the 4T60E first appeared in the '91 Riviera, and the 4T60 [440T4] was "new" in 1985. I'm sure if you do a quick web search you will find a lot of info about them.

did some reading and if 2-3 solenoid is bad the trans will shift hydraulically . any other input? thanks

JOE RIV 1 wrote:

did some reading and if 2-3 solenoid is bad the trans will shift hydraulically . any other input? thanks

how about you recap whats currently wrong, since you did a couple things and saw some improvement?

I am thinking you *might* need to adjust base line pressures to factory spec.  Some techs when they do fluid changes like to crank up the pressures and they push them too far which whack the transmission out over time.  Gotta stay pretty close to spec for these to work right as drivers. You need a scanner (tech II) as well as the typical gauge to read what you need to read in order to compare to specs, estimating it without actually measuring it doesn't really work. For instance the scan tool will read the pressure control solenoid amps when it's activated. If those amps are off spec, you have a problem sir.  Also, modulation of line pressure (and hence shift feel) are done by the vacuum modulator system.  If the base adjustments are near spec and your transmission is still acting up you may have a vac leak elsewhere from the vac manifold on the LIM.   In the "old days" I'd use a can of ether (starting fluid. Remember that stuff?), spray around the vac lines and see where the spraying caused the idle speed to increase.  Nowadays, on my own cars I just replace the lines/tees by age and feel.  If it's rubber lines with nylon tees, it's a few minutes and some line etc.  If like on the Riv it's rubber tees and nylon lines, I bought the factory manifold; if they stop selling them and I have to do it again I will just use the bits I need to switch to rubber lines/nylon tees. With the little custom lines - you know, the ones that look like question marks and stuff, and have different size nipples on each end - I glue together vac line and end adapters using tire cement from a bike tire patch kit, "GOOP," or black silicone cement.

Bottom line -- so anyway even though I *think* you might need to adjust the modulators so the base line pressures are at/near spec, I am guessing really.  The right thing to do is check the common sense stuff thoroughly (got vac leaks? wiring?), then use the FSM, scanner and gauges, and an afternoon to work thru the trouble trees.  A 2-3 shift at ~3000 is what you'd get with harder acceleration (hiway on ramp), so the issue might not be the trans it might be something is telling the trans that it needs to hold back on the shift or some such.  It's an interesting problem but not one I can solve sitting here.

Albertj

thanks for the post i checked for vacuum leaks with the starting fluid no luck! adjusted the vac mod every way. Need a scan tool.Going to check the speed sensor. thanks for the post!

I wonder if this might be a broken wire.

One thing that was common on Rivs of that vintage, a few years back, was for one or more wires to break at the harness plug to the ignition control module or the main harness block to the PCM. In either case it would break RIGHT at the plug and be hard as heck to find. I remember going back and forth with one member about it whom, when he finally discovered that was indeed the problem, posted a *very* nice writeup about how to find it... ostensibly because it was so tough to find.

So here is what I am thinking... I do not recall the transmission wiring harness being problematic. However, since that is how the sensor signals get in, to large extent, it would not be a total waste of time to check the wires and since there are not that many wires it will not take that long.

Typically with the ignition control or the main harness block at the firewall (goes to the PCM) the broken wires that were found had broken very near where the connector pin or socket was swaged onto the wire. Within about 1/8 inch or less. Also sometimes just wiggling and looking at the wire does not work to find a break because the insulation does not yield enough to be a telltale or sometimes the break is within the area of the wire that is covered by part of the swage. I think on that writeup the member had to use a Tech II to find the wire (read the problem sensor while wiggling the wires one by one).

What do you think Joe? Maybe a faulty wire?

Albertj

I had that problem with the cam sensor. Was a black wire at the firewall harness connector. Found it with the Tech2.







https://rivperformance.editboard.com/t4703p175-faq-p0341-camshaft-position-sensor-cam-sensor-timing-chain?highlight=Cam+Sensor

https://rivperformance.editboard.com/t4703p200-faq-p0341-camshaft-position-sensor-cam-sensor-timing-chain?highlight=Cam+Sensor

Thanks Larry, now I remember.  Very nice documentation of the work you did.  Even since then I have not figured out whether those wires work hardened over time, thus becoming brittle, or if they were work hardened during manufacture such that they became prone to breaking in use.  See http://gizmodo.com/the-incredible-fiery-process-of-making-copper-wire-1559282588 for a look at the copper wire making process.

Anyway, yes, this would be the first I'd hear of the wire break problem cropping up on the transmission harness but not the first time on this make/model/year car.

SO, Joe, Larry posted a link to his original post, it's good reading.  I am NOT saying your problem def is a broken wire, I have not seen that before on the trans harness location, but I AM saying don't rule it out and Larry's post helps make it really clear why.

time to start looking! I have ran into this problem before on some other cars. thanks guys will let you know what i find

well did some checking on some wires and no broke ones did fix one of the knock sensor chafed wire. cleaned the speed sensor no change have to get it scand

JOE RIV 1 wrote:

well did some checking on some wires and no broke ones did fix one of the knock sensor chafed wire. cleaned the speed  sensor no change have to get it scand  

Remember that the wire breakage might not be findable without a scan tool b/c the wire sometimes breaks inside the swage that is wrapped around the insulation. RE Larry's writeup.

Albertj

good write up! i pulled and striped back the ribbed insulation so im convinced the wires are ok but will re check when weather gets a little warmer(car dripped all over me today)

Well i still have to diagnose my problem but i picked up another trans for a great price with about 65k on it.If i do need to replace or rebuild the problem trans i would just swap them but before should i have the replacement one looked at or have it rebuilt with upgrades or fixed problem parts? I was told by the seller it shifted great and he is a member on the board here ! imput please

JOE RIV 1 wrote:

Well i still have to diagnose my problem but i picked up another  trans for a great price with about 65k on it.If i do need to replace or rebuild the problem trans i would just swap them but before should i have the replacement one looked at or have it rebuilt with upgrades or fixed problem parts? I was told by the seller it shifted great and he is a member on the board here ! imput please

No real input. If you have a mechanical issue then swapping in a working transmission should work. If you have an electrical issue it might or might not depending on whether the electrical issue is internal to the transmission. Only other thing I can think of is doing a web search on the problem. For instance I uncovered this with a Google search on "4t65s slow 2-3 shift" --> http://www.sonnax.com/articles/181-4l60-e-flares-on-2-3-shift-now-what. The article is about the 4L60, which is cased to be mounted longitudinal instead of transverse. Their approach to troubleshooting may help you with this one. You might want to try something like what they did before you pull that transmission. There are other interesting posts about the transmission, you'll see them in the web search. Watch out for the posts with something to sell, however Transgo and Sonnax are reputable and their aftermarket components do solve real-world problems with various transmissions including these.