Transmission Shift Kit
1999montana
06-13-2009, 08:15 PM
I read quite a few posts concerning hard shifts and what to do.
I planned to drain the oil and replace the filter and then step by step try to solve this problem using many of the suggestions found on the forum. I wanted to do them one at a time, until I got to a good result, or concluded that nothing would help the Trans but a rebuild.
The van had been hard shifting a few times last year, but with the cooler weather in the fall, it went away. It only happened twice that I know of last year.
Delinquent, I had failed to service the Trans at reasonable intervals. The first time it was power flushed and the filter changed was at 60,000 Kms. It should have at least had a service (dropped oil and new filter) at 120,000 Kms, but I elected to skip it.
This spring, the hard shifting returned, only it was more frequent and it was obviously time to do something. The van had 176,000 Kms on it when I decided to service it. Frankly, I was a little unnerved going anywhere near the transmission because auto trans has always been the domain of experienced techs from my experience anyway.
Last Saturday I dropped the pan, and examined what was in it. Nothing I wouldn't call normal wear and tear, and the fluid wasn't burnt either. So, I cleaned it all up, replaced the filter and grommet that holds it in, and buttoned the pan back up.
7 liters of Dexron III and a 700 ml bottle of Lucas trans fix later, it was running in pretty good condition. However, on Tuesday the hard shifting returned, only now with a vengeance. It likely had logged a code or two in the ECM (I never did scan it, but did I need to when all the symptoms were there anyway?)
The Lucas increased the viscosity of the oil even more, and it has cleaning and friction enhancing properties as well. I figured that the harsher shifts were the result of being able to finally build enough pressure with the new thicker fluid and consequently I was left with the same problem, only it seemed worse.
I finally decided I was going to do two things:
* Install the ZZPerformance shift kit for 4T65e transmissions
* Add an in-line Trans cooler.
Today, I dropped the pan again, filtered the trans fluid into two suitable containers and began the process of installing the shift kit.
I failed to flush the trans with Seafoam as recommended by many and in fact by a sales rep I contacted about a year ago. Since I had already changed the fluid and added the Lucas, I didn’t want to add ½ can of Seafoam and then have to refill with fresh oil again.
The guys at PartSource and I discussed the relative merit of flushing the trans and simply dropping the fluid and replacing it. The belief is that at this age and mileage, the bands and friction clutches have bonding agents on the substrate that may not take kindly to seeing a whack of new fluid, so mixing some new with the old, rather than flushing everything out is a less drastic way of introducing ‘clean’ into the transmission.
On a scale of 1 to 10, 10 being the worst, I would call installing the shift kit a 4. This was actually a snap to do. I was somewhat concerned about touching anything inside the trans case, but the instructions and pictures ZZPerformance has on the web were excellent and I proceeded to drop the accumulator module.
There are 4 bolts, 3 on one end and one at the far end that holds the accumulator to the bottom of the case. The lines / tubes wiggle out just like the instructions tell you, and the module comes away in one piece. I even managed to drain it into the tub of trans oil with getting a bath too.
I laid the accumulator in the bottom of the clean oil pan, and loosened all of the bolts that hold it together. Once the two halves were separated, I pulled the 1 - 2 accumulator servo out and cleaned inside the bore and cleaned the piston and springs too. Then I lubed the piston, added the ¾ inch spacer (they call them shims, but my definition of a shim is something you use to raise the spring pressure of vale springs for instance.
The ‘shims’ are actually spools or spacers made of nylon or Teflon that slip over the shaft the piston servo rides up and down on. The 1 - 2 servo also receives a ½ inch spacer on the opposite end. The 2 - 3 shift servo receives the same ¾ inch spacer as the 1 - 2, but then receives a ¾ inch spacer on the opposite end. There are two other spacers in the kit, a 1 inch and a ¼ inch so that you can firm up the 1-2 shift to the same level as the 2 - 3, or increase either the 1 -2 or 2 - 3 shift just a bit more with the 1 inch spacer. I found the 1 - 2 was always good and left it at the ½ inch spacer.
You lube each servo as you put it back in the bore, and I played with each of them to make sure they were moving up and down smoothly. There was a bit of gunk in the bores that the drop and fill didn’t clean out, so taking the accumulator apart and cleaning it probably didn’t hurt anything either.
Put it all back together, filled it with fluid and checked the level. Started it up and let it run for a bit while still up on stands.
The real test; - took it for a spin around the block. Nice crisp shifts on 1 - 2 and 2 - 3. What was really new was the crisp 2 - 3 shift. It was mushy before.
Am I impressed, you bet!
What we don’t know is whether the hard shifting has now been cured, but that will likely be determined tomorrow on the way back from bringing my son home from work. Nice long drive at highway speeds and then a nice hot climb up an 8% grade hill near us with the AC on. Should know if this shift kit helps with that kind of test.
If not, the in-line cooler is next.
I planned to drain the oil and replace the filter and then step by step try to solve this problem using many of the suggestions found on the forum. I wanted to do them one at a time, until I got to a good result, or concluded that nothing would help the Trans but a rebuild.
The van had been hard shifting a few times last year, but with the cooler weather in the fall, it went away. It only happened twice that I know of last year.
Delinquent, I had failed to service the Trans at reasonable intervals. The first time it was power flushed and the filter changed was at 60,000 Kms. It should have at least had a service (dropped oil and new filter) at 120,000 Kms, but I elected to skip it.
This spring, the hard shifting returned, only it was more frequent and it was obviously time to do something. The van had 176,000 Kms on it when I decided to service it. Frankly, I was a little unnerved going anywhere near the transmission because auto trans has always been the domain of experienced techs from my experience anyway.
Last Saturday I dropped the pan, and examined what was in it. Nothing I wouldn't call normal wear and tear, and the fluid wasn't burnt either. So, I cleaned it all up, replaced the filter and grommet that holds it in, and buttoned the pan back up.
7 liters of Dexron III and a 700 ml bottle of Lucas trans fix later, it was running in pretty good condition. However, on Tuesday the hard shifting returned, only now with a vengeance. It likely had logged a code or two in the ECM (I never did scan it, but did I need to when all the symptoms were there anyway?)
The Lucas increased the viscosity of the oil even more, and it has cleaning and friction enhancing properties as well. I figured that the harsher shifts were the result of being able to finally build enough pressure with the new thicker fluid and consequently I was left with the same problem, only it seemed worse.
I finally decided I was going to do two things:
* Install the ZZPerformance shift kit for 4T65e transmissions
* Add an in-line Trans cooler.
Today, I dropped the pan again, filtered the trans fluid into two suitable containers and began the process of installing the shift kit.
I failed to flush the trans with Seafoam as recommended by many and in fact by a sales rep I contacted about a year ago. Since I had already changed the fluid and added the Lucas, I didn’t want to add ½ can of Seafoam and then have to refill with fresh oil again.
The guys at PartSource and I discussed the relative merit of flushing the trans and simply dropping the fluid and replacing it. The belief is that at this age and mileage, the bands and friction clutches have bonding agents on the substrate that may not take kindly to seeing a whack of new fluid, so mixing some new with the old, rather than flushing everything out is a less drastic way of introducing ‘clean’ into the transmission.
On a scale of 1 to 10, 10 being the worst, I would call installing the shift kit a 4. This was actually a snap to do. I was somewhat concerned about touching anything inside the trans case, but the instructions and pictures ZZPerformance has on the web were excellent and I proceeded to drop the accumulator module.
There are 4 bolts, 3 on one end and one at the far end that holds the accumulator to the bottom of the case. The lines / tubes wiggle out just like the instructions tell you, and the module comes away in one piece. I even managed to drain it into the tub of trans oil with getting a bath too.
I laid the accumulator in the bottom of the clean oil pan, and loosened all of the bolts that hold it together. Once the two halves were separated, I pulled the 1 - 2 accumulator servo out and cleaned inside the bore and cleaned the piston and springs too. Then I lubed the piston, added the ¾ inch spacer (they call them shims, but my definition of a shim is something you use to raise the spring pressure of vale springs for instance.
The ‘shims’ are actually spools or spacers made of nylon or Teflon that slip over the shaft the piston servo rides up and down on. The 1 - 2 servo also receives a ½ inch spacer on the opposite end. The 2 - 3 shift servo receives the same ¾ inch spacer as the 1 - 2, but then receives a ¾ inch spacer on the opposite end. There are two other spacers in the kit, a 1 inch and a ¼ inch so that you can firm up the 1-2 shift to the same level as the 2 - 3, or increase either the 1 -2 or 2 - 3 shift just a bit more with the 1 inch spacer. I found the 1 - 2 was always good and left it at the ½ inch spacer.
You lube each servo as you put it back in the bore, and I played with each of them to make sure they were moving up and down smoothly. There was a bit of gunk in the bores that the drop and fill didn’t clean out, so taking the accumulator apart and cleaning it probably didn’t hurt anything either.
Put it all back together, filled it with fluid and checked the level. Started it up and let it run for a bit while still up on stands.
The real test; - took it for a spin around the block. Nice crisp shifts on 1 - 2 and 2 - 3. What was really new was the crisp 2 - 3 shift. It was mushy before.
Am I impressed, you bet!
What we don’t know is whether the hard shifting has now been cured, but that will likely be determined tomorrow on the way back from bringing my son home from work. Nice long drive at highway speeds and then a nice hot climb up an 8% grade hill near us with the AC on. Should know if this shift kit helps with that kind of test.
If not, the in-line cooler is next.
shampooguy
06-15-2009, 08:05 AM
Glad it worked out for you...I also installed the shift kit about 8k miles ago with positive results. Thanks again to BNaylor for outlining this fix in the Buick forum.
Automotive Network, Inc., Copyright ©2025