Thread: 4T65E Hard Shift-Solution

probaly not, lol im so use to it, it doesnt really bother me anymore it sounds supercharged hahaha

yeah everything is full, okay ill explain everything that its doing ill open a thread lol

Further update! I now have 20,000 miles on the 4T65E since installing the ZZP Shims, Dexron VI, and the 2 Long Double Stack Tranny coolers (18,000 GVW each!) outside of the radiator cooling. Today, I changed the fluid again with Syntec (Walmart) Dexron VI as well as the filter. About 6-9 months ago, I decided that I would purchase the Transgo shift kit and would replace the ZZP shims with the Shims and new springs for the 1-2, 2-3 accumulator since I felt that it was a more complete solution/kit than just the shims.

First, the transmission fluid (Dexron VI) looked really clean/good at this change-the fluid was really still looking very red (Like when fresh) and there was almost nothing in the pan-no metal particles/no silt. I was surprised!

I did remove the ZZP shims and installed the shims and new springs on the 1-2, 2-3 accumulator pistons from the transgo shift kit. Filled it up with 7.5 QTS of Dexron VI and went for a ride.

The 1-2 shift is definitely faster than before and so is the 2-3 shifts but unless you knew the difference before, you would not notice any harshness at all. It feels all very normal, unlike the transgo shift kit I installed last year on my 94 mustang GT convertible with the crap AODE automatic-that kit transformed the AODE into a very fast shifting auto with crisp firm shifts. Not the case here but not the objective either.

No harsh shifts as I would have expected at this point after the last 1.75 years since I started to attack this issue. I will keep all of you updated. Hope this helps!

heys guys let me know what you think. i have this problem with my intrigue, same tranny. car has 184k on it just got it about 10k ago have no idea how it was treated. the problem only happens on longer drives when car gets hot other than that it perfect. tranny fluid is nice red. brought it to one tranny shop and they scanned it and said i needed a rebuild that it was slipping they didnt drop the pan even. another shop said i needed a pcs. should i try the kit or do i have to many kilometers? i live in canada so dont think i need the tranny cooler till summer. what do you's think any info is appreciated thanks.

The transgo shift kit is cheap. Give it a try. I would imagine you will be set if that is the only problem. I use my GP weekly as a airport/train station car and it has been perfect since the installation of the shift kit and coolers! 20,000 miles now!

Can I get an update, just read all 5 pages of this and would like to know how the car is now? I am having this problem on my 99 gp gt and found this very informative. Thank you!

Its been almost 2 years since I installed the Transgo Kit. My Chevy Venture is still running well.

My Olds Silhouette is perfectly great as far as the P1811 / hard shifting goes after 2 yrs/40K miles. There is absolutely no reason whatsoever not to do this modification. If I bought a brand new car with a 4t65e in it, I would probably do this.

In my case I still have the torque converter clutch lock up issue. However, as near as I can tell it is an entirely separate issue. Two shops have put it on a scanner & swear that all solenoid functions & line pressures are in order - leaving a mechanical issue with the converter clutch itself. I don't know if I believe them (not that I think they're "lying" - I just don't think they care to spend much time on sorting it out), but I don't have the tech equipment necessary to figure it out myself.

So - as much as I HATE the idea of transmission additives - a bottle of the Lucas Transmission fix stuff is keeping the TCC issue mostly under control. DO NOT use this stuff if you have a vehicle that you care about and plan to keep for a long time. I'm just limping mine along for as long as possible because I think it is a complete piece of junk, and will be replacing it rather than spending any real repair $$ on it.

I used the ZZ Performance shift kit plus I bypassed the radiator oil cooler with two Hayden Maxi-Kool XL Transmission oil coolers mounted in front of the a/c condenser. This stopped the hard shifting by keeping the trans below 140 degrees. The kit alone did help, but in my car keeping the trans fluid cooler than engine coolant temp was the best fix. I have about 15,000 miles on the ZZP shift kit and 220,000 miles on this 2000 Pontiac Grand Prix GT. I purchased this car at about 144,000 and my wife loves it. Yes, the hard shift when hot was the reason, among others, that the last owner sold it. It has been a restoration project for me. Love that stuff! Many thanks to all the contributors here at gpf, especially, jbamonte, for this fix.

Update! Just passed 35,000 miles since the transgo shift install and the (2) 18,000 GVW double stack coolers running outside of the radiator (they do all the cooling all the time). I have not had a hard shift issue now for over 2.5 years, drive the car routinely at 80-85 mph (Trip to Montreal at those speeds netted 30.5 MPG recently in June 2012-unbelieveable)! Never got that mileage with my other 98 GP GT with the 3.8). The transmission is absolutely perfect with no signs at all that there was ever a problem, 125,000 miles on the 4T65E and the 3.1 with magna flow duals, ubend delete, and 2.5 inch stainless pipes (GMPP exhaust which was just the magnaflow kit for the 3.8 motor). Again, this fix appears durable for the long term if your only problem is a hard shift problem when hot! Pretty unbelieveable that the "experts" seem to some how missed this fix which is MUCH easier than dropping the tranny to change solenoids, and at the end of the day will contribute greatly to the longevity of the 4T65E tranny which gets killed by the tremendous heat retention running the tranny lines through the radiator.

Just hit 130,000 miles on the 4T65E with the Transgo shift install and the (2) 18,000 GVW Long Double stack trans coolers doing all the cooling outside of the radiator-almost 40,000 miles with zero harsh shift. No issues! Just an update!

Figured I'd update too.

The shift kit completely silenced my pump whine/hard shift/P1811 issues. I never solved the issue with TCC lock-up but Lucas Trans "fix" helped it considerably. Even so, I always hated driving the thing. I don't recall if I mentioned it when first reported, but I would never put any "transmission fix" additive into a vehicle that I cared about and wanted to keep on road. None of them will "fix" anything. So just advice, I guess. I don't advocate using these things and only tried it myself b/c there was no way that I was going to spend any big $$ on this POS van ('00 Olds Silhouette).

In any case, oddly enough, I kept the transmission limping along pretty well but my van went to the scrap yard with a blown head gasket at about 170K. I was never so glad to see a vehicle go. It was the biggest piece of crap I've ever owned.

In any case, if you have a GM vehicle with a 4t65e in it - just do the shift kit & cooler even if you don't have any problems. Whatever the root cause of the slipping that leads to the P1811 code, it is really bad for the clutch packs. I am convinced that the shift kit will prolong the life of the trans.

My 99 GT is doing the same thing. It will shift smooth until the temp gets about 175-185 on the gauge then it will start jumping. I guess its getting worse now because it only use to start jumping at 210 which is normal temp. However I do have a heavy foot and tend to drive aggressively. But not on hot days where it would start jumping. Usually at night in cooler temps. Although I race my car I also maintain it very well with tune ups and fluid changes. My most current issue is now my transmission is slipping at wot from 2-3 but if I drive normal it goes in every gear smoothly until the tranny heats up :P

Just hit 145,000 miles on tranny with the the Transgo shift kit and the 2 Long 18,000 GVW coolers in the grille doing all the trans fluid cooling OUTSIDE of the radiator. Zero hard shifts since the installation 4 years ago and working perfectly. Fluid looks great at every trans fluid and filter change that I do every 25,000 miles now as the trans ages. Cheap insurance!!! Dexron VI, BTW, not Dexron III, for those that have doubts about using the newest and superior Dexron VI Fluid in the 4T65E transmissions. Trans fluid-Supertech Dexron VI (8.5 QTS) and filter are about $50. I am being overly cautious but under no circumstances should a stock tranny with stock radiator cooling go more than 30,000 miles between changes due to the fragile design of these trannies and the radiator "cooling". I could probably safely go 50,000 miles between changes with my setup but why risk it for $50? Hope that helps!

I'd give the shift kit a try hadn't I just dumped $80 worth of full synthetic in, lol.