Thread: 4t65e HD Rebuild (Question is for Trannyman95 or any other Tranny GURU)

LOL I feel ya on that note!

I've noticed in my trans it occasionally shudders in drive when I take off. It almost feels like wheel hop but I'm convinced its the trans. Trans has 70k on it right now and it happens probably less than 5% of the time. It occurs most often at like 30% or so of take off power. If I mash the gas it just breaks the tires loose. But if I decide to accelerate a bit quick it does this.

What are the likely areas of concern. I have a wbody shift kit with DHP 1.5 bin file which is currently not been modified. I have a snap on scanner so I can read a bunch of trans data if necessary. No trans codes as of right now.

So I was going through my ATSG update book and it mentions the PCS is likely the culprit which I've heard is notorious for going bad in our trans.

Trannyman

It says in the update book that prior to installation, you should turn the New Desgin PCS (OEM # 10478146) adjusting screw an 1/8 turn, as well as installing the Boost valve sleeve kit (Sonnax #84754-30k). Do you typically turn the adjusting screw in the new PCS or do you just install the new one along with the boost sleeve kit.

Yeah those two parts are the most common causes. The solenoid has a pretty bad track record and will cause low pressure if acting up. Turning in the screw as mentioned in your book will slightly raise pressure but not much, but can be enough to help cover up other potential problems. I use Borg Warner style pressure control solenoids which look completely different and I havent had any trouble with those to date. The also have the adjustment screw which is peened really tight and I dont adjust them during my builds but you could turn it in if just replacing a bad old solenoid.

Sorry guys, here is a pic of the contents of a Transgo SK4T65E shift kit

I'm looking at that picture, and I'm not sure what the bag on the right is for.

Bag on left is for acumulator
Then there's the rubber seals for 3rd and reverse

How does this kit take care of the shudder on takeoff from 1st? I don't see how this would fix the boost valve in the Valve body if that was the problem.

The bag on the right is a new boost valve and spring that uses the factory sleeve. The Transgo valves are longer and have more support and also ride in fresh areas of the bore. Together there is more support for less wear as there is more surface area for the valve to ride on. There are also building tips in the instructions that are standard parts to keep an eye on during a rebuild.

Would you say the transgo boost valve is enough for a slightly worn valve body. Or is the sonnax boost valve and sleeve kit quite a bit better since there is a sleeve that actually goes in place to take care the sloppy bore.

I have been using the Transgo kits since they were released, around 02/03 IIRC and I have never had a problem with them. The Sonnax valve is definately a nicer piece but the Transgo parts also work fine.

Any recommendations for a good torque converter that has a stock stall speed of is very similar as it is my daily driver. I'm not planning on putting down more than 300 hp and am also looking for a torque converter that doesn't use kevlar clutch as zzp's or wbodystore. I want the similar material that they use in oem which is a carbon based one which I know Raybestos sells their SW Carbon lining which is supposed to be good from what I read.

Anyone use Rebuilt Precision torque converter from New Hampton?

or should I go with a torque converter from Transtar, they also sell Recon torque converters?

Also what is actual torque converter stall speed for a 4t65e-hd (I know its less than 2500 RPM)?

Stock GTP converters already stall in the 3K rpm range with mildly modded M90 cars and that is why I never suggest using anything else, stall speed wise as it is plenty. I have used Precision converters for the past 4 years and never had a problem with one for any make or model car and I have probably used a few hundred for 4T65E transmissions and again no problems even on cars running into the low 12 / high 11 second range and the majority are daily driven street cars that see many miles each year. I am also not a fan of aftermarket converters because of the lockup clutch linings used. Kevlar was ditched back in the 90s by many converter builders because it caused too many problems and many of them because of PWM lockup style transmissions. If the pcm or transmission is modified to work with this then its not a big deal, but for guys looking to just throw a different converter in the car then it can be asking for problems down the road. There are many good converter companies out there and many stock replacement converters are all built the same.

A Transgo shift kit is not the answer for firmer shifts or to help existing problems. If you want firmer shifts then a Thrasher or Intense shift kit is the way to go as it not only gives you the firmer springs but also selective firmness shims that may help out.

What ZZP and Wbody store sells are nothing more than spacers that you can buy from a hardware store and follow the DIY shift kit instructions floating around on the other forums. Some guys say they really dont get much difference out of doing this, I installed one about 3 years ago and it made next to no difference on a good working trans. There is more to making firmer shifts than just shift timing alone. Since you have HPT then you can go into the shift firmness tables and up those numbers, and also go into the amperage tables and work on the far right side of the table, low amperage, and lower the numbers there which will also firm up the shifts.

do you have to drop the whole tranny out to put in the boost valve or can you just lower the engine and everything a little bit and get at the side of it?

Look up a How to 4th clutch hub write up I did. You can get the VB and channel plate off by lowering the drivetrain a bit, while leaving it int he car.