Thread: 4T65E-HD mods with filter change

I bought a used Regal GS with a rod knock i have a motor for it and am getting ready to install it.I know the trans are weak links in these cars, the fluid looks great so maybe they serviced it and it will last awhile.I have a trans core i will have it rebuilt if it gives me any problems does anyone know where to get a FULL HP kit for this trans? but in the meantime i wanted to pull the pan and replace the filter see how things look. Other than the PCM trans mods i was looking at the kit Wbody store sells its basically a filter kit with some plastic shims has anyone used this ? I think it would be worthwhile but i noticed the other kits are 99.99 and have more options and this kit just seems to have the shims.Anyone have any input? Also what fluid should i use? I can get TCI fluid reasonable less than 20 bucks a gallon but some of the HP fluids say not for use in 99 or later transmissions which i dont really understand? my car is a 98 but i know the 99 trans is the same so whats up with that? I do not want to pay for some overpriced syn fluid and i will only be able to replace half the fluid anyway so i am trying to add some performance,life,reliability if at all possible.??

Shift kit will help, but in order to have a true performance trans it needs to be built properly.

Fluid wont matter much, most seem to opt for Dex VI though.

Yeah i saw that Trans Go kit for about 60 bucks, i think i will go with that but still dont know about the fluid not that it will make a big difference but it has evolved a little since DEXIII

Ya thanks guys the local trans guy uses DEX III in everything. I can get TCI fluid for 20 bucks a gallon not sure if it would do anything claims to run cooler blah blah blah but who knows.A lot of people swear by this lubeguard additive. I had another Regal GS and it had 175,000 on it but ran great the trans was a GM reman which was probably replaced under warranty early on judging from the crap in the pan.It also had what looked like a valve body bolt broke off laying in the pan but all the bolts where there. The car had been sitting a while and it pulled kinda weird which is why i changed the filter but it would hold the gear so long i would let up on it cause it was near 6000 but it shifted real funny at times.I will put the trans go kit in the fluid looks good, service sticker under hood showing service at 70,000 showing 127,000 now.I have seen a lot of these trans go bad even in park avenues driven by older people so.Hope it holds up I have a core if needed.

Bill i was doing some reading last night and saw you on some other sites with trans mods.I thought this transgo kit would work best but intense says it is not a perf shift kit.I want a nice crisp shift with no slip i would like it to atleast chirp second if not a little better.Is this kit what i want or should i just shim it or buy one of the other kits like the Shift Tech Products or similair? Also intense says the transgo kit needs the accumalator seals and or other things to install? If i do shim it now do i use a middle shim or go all out i plan on having the PCM flashed but it may be a couple weeks after i change the fluid and filter and want to atleast shim while i am in it. I think ZZP says to use a middle shim if your later going to raise pressure and shift points with PCM? I am just reading not trying to say anyone is telling me anything wrong at all.Of course both these companies want to sell their product but some of these things they said sort of makes sense?I know one guy said he loved the transgo kit but that it was not a crisp shift. From what i read last night you seem to be a trans guru so i am asking you?

So it seems for what i am after i would be better off with shims and the spring change.They have a medium and hard shift spacer as you know i was thinking i would get something in between both of those.Then it says to put a 2-3 spring in the 1-2 accumulator if i am correct.So i only need one of these right?The thread is kinda dated i searched a little and the spring #24203977 the info wont come up or its not available,do you know if its still a good number?possibly where i could get it?Do you think these mods would be more suited to what i am after? If i ever trashed this trans i would build the core i have and fully mod it,i hope i dont have to but. I heard the DEX 6 gives it a firmer shift i know you said you did everything at once so you couldnt tell.