'92 Caddy transmission problem.

[Tony Hanna]

The trans in my '92 Eldorado has been acting weird. When coming to a stop quickly sometimes it acts like I threw the shifter into neutral and the engine free revs when I try to take off. Once stopped when it's doing this, I have to manually select first. Once I pull the shifter into first, I can immediately put it back in OD and it's fine again (shifts normally) until the next hard stop. Gentle stops don't affect it.

Initially I thought it was low on fluid and the pump was picking up air during a hard stop due to the fluid sloshing around. Fluid level is fine though. Any thoughts on what could be causing this? Maybe a sticky valve that inertia is helping to stick during hard decel?

Thanks,

Tony

[black86glhs]

It sounds like a valve body issue to me. Problem is that on a 4T60-E, the valve body in the side pan, not the bottom pan. Much more involved to get apart.

[88_pacifica]

Bryan is right. The VB is probably sticking. This is a common problem on those tranny's if they aren't serviced religiously. :(

You could "try" to run a detergent through the trans fluid then change it, but if there is a buildup or varnish on anything, it "prolly" won't help much. I would take it in as that trans is difficult to service which is why I hate Caddy's...

[Tony Hanna]

It sounds like a valve body issue to me. Problem is that on a 4T60-E, the valve body in the side pan, not the bottom pan. Much more involved to get apart.

I wonder what the chance is that a good flush, a new filter, and some of that lube guard stuff would sort it out? I'm not usually one for trying "snake oil" treatments, but if it's just a valve hanging due to some dirt...:)

[Tony Hanna]

Bryan is right. The VB is probably sticking. This is a common problem on those tranny's if they aren't serviced religiously. :(

You could "try" to run a detergent through the trans fluid then change it, but if there is a buildup or varnish on anything, it "prolly" won't help much. I would take it in as that trans is difficult to service which is why I hate Caddy's...

I'll give the detergent a shot. Taking it somewhere isn't really an option as I'd probably have more in service than I paid for the car. Might look for a good used trans if I can't get this one sorted out though. Either that or just live with it if it's not going to cause the trans to fail.:nod:

[88_pacifica]

IMO, that's what I would do and any other trans you stick in might have issues as well.

A good flush would probably help and the symptoms are not like a set of bad bands. You should be ok and just make sure to get the fluid level right, those trans' are picky...

[Tony Hanna]

What else did they use that trans in? Anything that also had a 5spd as an option?:D
That might be a fun project to take on after I've got the Spirit sorted out well enough to use as a daily driver.

[88_pacifica]

What else did they use that trans in? Anything that also had a 5spd as an option?:D
That might be a fun project to take on after I've got the Spirit sorted out well enough to use as a daily driver.

Again, they're definitely pricey since they are computer controlled and have specialized parts.

http://www.automotix.net/transmissions/1992-cadillac-eldorado-4_speed_automatic_transmission_fwd-4t60e.html

Common TCC related issue which it might be:
http://forums.automotive.com/70/6242025/transmission/gm-4t60e-tcc-problem/index.html

They were common in many different 90's applications, but I'm not sure what the parameters are for each application(tq conv, shift points, etc). While computer controlled, it can be very touchy based on the application. I would try and find another one from that particular model in case there are some specific RWD apps that are unique. GM was notorious for making the same trans specific to each vehicle, for example the GN vs Monte's vs low powered cars of the late 80's(200r4). Although they are the same trans, they are totally different beasts all together. :(

[Tony Hanna]

Thanks for the links.

That's actually not as bad a price on the replacement trans as I feared.

[88_pacifica]

Thanks for the links.

That's actually not as bad a price on the replacement trans as I feared.

Still not cheap though. A good trans shop could get you pretty cheap[cheaper than that] and some of the internals could obviously be reused. I would think that $850 would be about right, but you'd have to poke around. Before you do that though, I would consider a new VB. Depending on your mileage, that may be all you need. :thumb:

[Tony Hanna]

Yeah. maybe replace the VB or go through the one that's in it. I need to buy a manual for that trans to see what I'd be getting into. I've been into 2004r, 700r4, and 4l60e transmissions before but not any GM fwd stuff yet.

[black86glhs]

I can tell you that it is getting to it that is the worst part. Once you have the wheel off and you drop the subframe on the drivers side, it is cake. But then again I was a GM technician for 8+ years. Once you get the side cover off, it pulls off just like a rear drive, except it is vertical instead of horizontal. You definately need some vasaline or trans gel to hold the check balls in.
I'll take a look and see if I still have my factory trans manuals. I could be persuaded to make some copies and send them your way.:nod:

[Tony Hanna]

Thanks Bryan!
I'm going to try a flush, filter, and some detergent first though. If I end up having to get into it any farther than that, it's going to have to wait until the Spirit is back together. I don't want to get into a project that's too involved without having something else to fall back on as a driver.

[black86glhs]

No sweat. Personally I think if you do what you said above, it should help it. Still gonna check on the trans books, just in case. Gotta remember where I put those....:confused2:

[RoadWarrior222]

Lucas Transmission Fix always seems to work relative miracles for me for any issues related with gunking up, seal seepage, etc. gives you more "grab" usually too. Takes a week to "drive in" usually.

Kept a Tempo on the road 50,000 miles past knackered.

[Tony Hanna]

I was thinking of trying that lubeguard stuff. I've read some good about it here, and it had the governor in the Spirit sticking a little less frequently (before the excessive line pressure killed the trans). Hopefully the detergent in some new fluid will clean things up enough, but I'll try the lucas or the lubeguard if it doesn't.

[RoadWarrior222]

Hmmm just thinking, how similar is the 4L60 to that? When I had a POS S15 Jimmy it did similar stuff in colder weather until I changed out the fluid, behaved after that. Guess something was gummy somewhere.

[black86glhs]

4L60 is rear drive and VB is in the bottom pan. They work on the same principles, so its very likely it will work for both.

[Tony Hanna]

The thing is, I ran a whole case of new fluid through it when I got the car (cooler line into a bucket feeding the new fluid through the dipstick tube). I went with type f to firm up the shifts a little. I wonder if that has anything to do with it?

[JohnnyIroc]

damn General Motors cars...

[black86glhs]

The thing is, I ran a whole case of new fluid through it when I got the car (cooler line into a bucket feeding the new fluid through the dipstick tube). I went with type f to firm up the shifts a little. I wonder if that has anything to do with it?Tell me your Kidding!!!!!!!!

[Tony Hanna]

Tell me your Kidding!!!!!!!!

No, why? It's the only way I've found to completely replace the fluid in the converter. I don't let the car run long enough to run the trans completely dry, just alternate between pumping out and refilling until the fluid coming out of the cooler hose is fresh, then reattach the hose and top the fluid off.

The plan was to change the fluid out like that, drive it for a few hundred miles, and then drop the pan and replace the filter. Unfortunately, the filter change never happened.:o I'll get to it this time though.

The type F worked well for firming up the shifts. I started using it after installing a couple shift kits in different GM transmissions and seeing it recommended in the instructions.

[RoadWarrior222]

Clogged filter might be restricting pressure, which could cause issues.

This one is at least partially electronic though isn't it? I'd do a key dance see if there's a VSS or TPS code. (Can't remember how it is with GMs of that era, think you need to short across a couple of pins on the connector to enable engine light codes.)

[black86glhs]

On a TH350 or TH400 sure, but not on a more modern front wheel drive trans. They are designed for the Dexron III. I'll bet that is causing issues. I realize you can use other fluids in other trans, I use ATF+3 in ford 4 spd autos to fix the TCC shudder, but I would never use type f in a fwd trans. Thats just me.

[Tony Hanna]

Clogged filter might be restricting pressure, which could cause issues.

This one is at least partially electronic though isn't it? I'd do a key dance see if there's a VSS or TPS code. (Can't remember how it is with GMs of that era, think you need to short across a couple of pins on the connector to enable engine light codes.)

I'll have a look. This being a Caddy, all the diagnostic information gets displayed on the information center by pressing the right combination of buttons on the climate control. Pretty sure the only code it will give me is for the egr though (been getting that one intermittently and clearing the codes to get rid of it).


On a TH350 or TH400 sure, but not on a more modern front wheel drive trans. They are designed for the Dexron III. I'll bet that is causing issues. I realize you can use other fluids in other trans, I use ATF+3 in ford 4 spd autos to fix the TCC shudder, but I would never use type f in a fwd trans. Thats just me.

I might switch back then. Never had a problem with type F in the 4l60e in the z28, so I figured it would be ok.:o

[black86glhs]

I'll have a look. This being a Caddy, all the diagnostic information gets displayed on the information center by pressing the right combination of buttons on the climate control. Pretty sure the only code it will give me is for the egr though (been getting that one intermittently and clearing the codes to get rid of it).



I might switch back then. Never had a problem with type F in the 4l60e in the z28, so I figured it would be ok.:oJust to be clear, I'm not saying your wrong. I "personally" wouldn't use type F in a FWD. It may have nothing to do with it. It may just be a valve in the valve body that has developed a burr or the passage has one. Bench top diagnosing is sooooo much fun!!!!:thumb:

[Tony Hanna]

I'm really hoping it's not the type F as the shift feel is about perfect with it. With the dexron it was mush. With the type f, it's still not hard but firmer. More what you'd expect out of a car labeled as a "touring coupe".