2006 Rendezvous Transmission issue

[motc777]

Specs on vehicle:

2006 Buick Rendevous
3.5 L
Bought it used about 5 months ago, which had one owner, and mileage at the time was 183K
Current mileage now is 194K
Have no idea, but doesn't look like any transmission work ever done.



I read another thread about this I think, but thought I would start my own to make sure what I am seeing happening is actually the problem.

For a few weeks, off and on, and it was more off than on, when taking off from a dead stop, it would seem like the engine would rev up and then engage into first. Sometimes it would just kind of rattle and jerk as it was taking off and then I was fine. That was, until last night.

I started down the road, but when shifting from 2nd to 3rd, it just wasn't happening. Engine would rev to 4K RPM's and I would just coast until a dead stop. When I tried to go forward, I didn't even have first, but if I shut the engine off and back on again, it would engage in first, but then it wouldn't go from second to third. I tried putting some Lucas no slip in to see if that was the issue, but that didn't help. Also, at idle, I hear a whine noise coming from the drivers front wheel area. I stopped at this point and got a tow back home.

I have a scan tool, but it is not registering any DTCs, but clearly there is something wrong. 😕

So I looked around and I'm thinking that I might be having a problem with a "shift solenoid"? My question is, in properly diagnosing this, what is recommended in terms of procedures? Also, is there more than one solenoid down there? From research it seems there might be, but honestly, I cannot tell. If I am going to get far enough that I am taking the side of the tranny off, I want to go ahead and replace any and all solenoids as a preventative maintenance thing, as well as dealing with the current issue.

Finally, it seems that the auto parts stores are asking me why transmission do I have. I think there are two kinds, 4T-65E and THM440-T4. I have no idea where to go to verify this?

Any help is appreciated. I've been learning a lot on this site about GM stuff.

 

[MelsRegal]

I would start with dropping the pan to replace the filter and fluid and to see how much debris is in the pan. In addition according to the AC Delco site you have a 4T65E trani

 

[motc777]

Thanks for the suggestion. So to make sure I understand, are you saying that I should replace the filter and fluid, and then try to drive it before looking at the issue of solenoids?

 

[lrj975]

no, drop the pan just to see the amount of debris on bottom which is the clutch plates worn away. new fluid and filter at this point is pointless.

conventional wisdom says at 194k with no service ever means a complete rebuild.

Valve body service replacing solenoids, seals, o-rings, springs is half the job which could restore performance. There's EPC, TCC lockup, 1-2, 3-4 shift solenoids, manifold pressure switch, boost valve. nice little project.

The other half which requires trans removal are the clutch discs, bands, gaskets, bearings, gears and related hardware as needed.

Transmission will set lots of P07*, P18* try another scanner.

all RDVs are 4T65-E, 4 speed, transverse, 65 load rating, electronic
THM440-T4 is an earlier 4T60 from the first 80s FWD, followed by 4T60-E in the 90s

 

[motc777]

no, drop the pan just to see the amount of debris on bottom which is the clutch plates worn away. new fluid and filter at this point is pointless.

conventional wisdom says at 194k with no service ever means a complete rebuild.

This I am not sure of, but here is what I found. When I dropped the pan, it literally was black and brown. At the bottom of the pan, no metal at all though. Not even so much as metal dust on the magnet. It just was gooey on the pan itself, and when it drained initially, it looked like used motor oil.

I let it drain all night and all day today. The gasket surprisingly enough looked awesome, but I decided to put a new one on that came with the filter.

Valve body service replacing solenoids, seals, o-rings, springs is half the job which could restore performance. There's EPC, TCC lockup, 1-2, 3-4 shift solenoids, manifold pressure switch, boost valve. nice little project.

About this. I have seen that there is a common problem with solenoids, specifically the one's you mentioned here.

Transmission will set lots of P07*, P18* try another scanner.

Should I also be seeing some sort of check engine light on the instrument cluster as well? If so, I am currently not seeing that at all. In fact since the trouble started, has not come on not one single time. There are no stored or pending codes on my scanner.

all RDVs are 4T65-E, 4 speed, transverse, 65 load rating, electronic
THM440-T4 is an earlier 4T60 from the first 80s FWD, followed by 4T60-E in the 90s

Thanks for clearing that up. BTW, if I were to buy the shift solenoids, do you know the part numbers? I am having a hard time figuring those out.

 

[lrj975]

This At the bottom of the pan, no metal at all though. It just was gooey on the pan itself, and when it drained initially, it looked like used motor oil.

the friction clutch discs and bands surface is what wears away, so not really metal, combined with very old transmission fluid is what this sounds like. The valve body has channels and check valves that could get gummed up with this, very tight tolerances, which could be preventing fluid pressure from activating the shifts. Or the friction clutch discs are just plain worn down to nothing and fail to activate.

The gasket surprisingly enough looked awesome, but I decided to put a new one on that came with the filter.

if the old gasket has ribs all around, then that is the original gasket, which is better than the replacements, and can be re-used, no gasket sealer needed, torque not over tighten the bolts.

Should I also be seeing some sort of check engine light on the instrument cluster as well? If so, I am currently not seeing that at all. In fact since the trouble started, has not come on not one single time. There are no stored or pending codes on my scanner.

well maybe maybe not depending on the point of failure. There's 25 P* codes that could set depending on what the computer interprets.

shift solenoids, do you know the part numbers?

check ebay search on '4t65e solenoid kit' and sellers package them together. There's also valve body rebuilds with everything cleaned and installed.

 

[motc777]

Trying to change shift solenoids. I was watching a video that says you have to disconnect the rack and pinion before lowering the cradle. Thing is I've lifted that boot as far as it will go and I cannot find a way or a bolt to remove to do this. On the rendezvous is this even necessary? The video was about the same transmission but on an older Malibu.

 

[lrj975]

Trying to change shift solenoids. I was watching a video that says you have to disconnect the rack and pinion before lowering the cradle. Thing is I've lifted that boot as far as it will go and I cannot find a way or a bolt to remove to do this. On the rendezvous is this even necessary? The video was about the same transmission but on an older Malibu.

yes necessary as there are bolts all around the side plate and the trans needs to lower. Whatever video you have, the rack is likely disconnected and subframe lowered or removed.

The rack gets disconnected by removing a pinch bolt on the lower intermediate shaft, iirc 11mm, near the rack. That lower bolt is an awkward spot, but workable, can't really see it, need to feel around, big pita especially getting back on. The intermediate shaft will slide off when the bolt is removed, and rack is lowered.

The 2 blue dots is the lower bolt location.

 

[motc777]

yes necessary as there are bolts all around the side plate and the trans needs to lower. Whatever video you have, the rack is likely disconnected and subframe lowered or removed.

The rack gets disconnected by removing a pinch bolt on the lower intermediate shaft, iirc 11mm, near the rack. That lower bolt is an awkward spot, but workable, can't really see it, need to feel around, big pita especially getting back on. The intermediate shaft will slide off when the bolt is removed, and rack is lowered.

The 2 blue dots is the lower bolt location.

Thanks for this. I decided to work around this by removing the driver's side rack bolt from the rack and pinion. It was easy for me to reach and accomplished the same thing. Got this idea from someone else on the internet who did it.

The major issue I am having now is, I am doing reassembly and all the cradle bolt holes are lined up. Of course on the passenger side I did not remove, but loosened them, and on the driver's side I removed both of those. The drivers rear one is lined up perfectly, but the front drivers is off by about half an inch. I have tried jacking things and lowering things have a different dozen ways and still no luck. It's as though the cradle needs to come more the direction of the driver's side and it would line up perfectly. What is strange too is that back in the engine bay, the dog bones are lined up perfectly too.

This is really holding up the whole process. Everything else is assembled like the axle, side cover back on, etc. Any tips are appreciated.

 

[lrj975]

sounds like excellent progress.. but not sure what advice for that, keep trying, take a break, keep trying, needs a dozen +1. Maybe try to tighten the 3 good bolts and somehow the last will line up

 

[motc777]

sounds like excellent progress.. but not sure what advice for that, keep trying, take a break, keep trying, needs a dozen +1. Maybe try to tighten the 3 good bolts and somehow the last will line up

Spoke with a mechanic friend of mine here where I work. He works for a tranny shop in spare time. He said the last bolt sometimes can be a pain. He said get a crowbar and muscle it over. That's what he's had to do with a lot of vehicles. I'll let you know. My brother in law is helping me out tonight. Might take a two man job to complete.

 

[motc777]

Well, My brother in law helped me by getting a big ole prybar and pushing the cradle my direction. Lined right up and got it secured in the hole.

Everything else with reassembly went well. The only thing is, I broke something up near the engine. Now there is a vacuum leak. But back to the tranny.

I replaced two shift solenoids, down shift solenoid, and the TCS. I took it out tonight and gingerly started driving but already noticed a huge difference in shifting and frankly, power. But I got a good scare when it shifted from 3-4 as I was accelerated when I hear a screech right when it shifted. It did that maybe one other time while test driving it for 30 minutes, but it shifts like butter now, and is awesome!

This vehicle has 196K on it. don't know how much more I will get out of it. I am only out $300 in parts and fluids. That's better than a $1K tranny overhaul. Thanks again for everyone's help.