My experience with the 2004R is that if it is not put together properly with the right components, it will turn into a nightmare really quickly. Unlike the TH-400 or TH-350, the 2004R is a very finicky transmission. In stock form the 2004R will not last behind an Olds 455 (even a stock 455). Billet parts are needed (billet forward drum, billet input shaft) and better clutches and higher line pressures. Stock line pressures with high torque applications, will make the clutches start to slip.

In manual 1st gear, line pressure should be above 250+. In Drive, at full TV, the line pressure should be 225- 275. If it's not, you have issues. Low line pressure will destroy a 2004R faster than anything else.

The 2004R when it shifts from 1st-2nd gear, it applies the band which holds the drum, the trans then shifts into 2nd gear. If the line pressure is low, the band will not apply and hold correctly, causing it to slip and burn up the band. Eventually this will cause the band to wear and fail. You will then lose 2nd gear and the trans must come apart and be rebuilt. Proper higher line pressures are needed to apply and hold the band in high torque applications. Hence the 225psi (absolute minimum) to 275+ psi (ideal) line pressure is needed when shifting 1st-2nd gear in a 2004R.

Also, DO NOT use a stock 2004R trans pan with a stock 2004R trans filter on a performance vehicle. The stock pan was too shallow and the stock filter with it's top pickup was a disaster when it came to sucking air and creating pressure drops in the the trans. The Buick guys discovered this quickly. Tests were done with a stock pan and stock filter, on a stock GN. When accelerating the fluid sloshed to the back of the pan and the filter would suck air in and line pressures would drop to under 100psi during WOT applications. This would in turn burn out the clutches and band in short order.

Get a deep pan and use a 700R4 trans filter (bottom feed) in a 2004R. Otherwise, you will be rebuilding the trans once again in no time soon.

 

Thanks for the input. Cutlass has a stock 350 in it now, but I’ve got a 455 that will be mildly built when I get back - so, I purposefully built this trans to handle 550 ft/lbs. the only thing I didn’t put in it was billet clutch piston apply rings (turbine shaft, OD ring, fwd housing/shaft, sun shell, roller bearings all upgraded) See post #36 for my pressures - didn’t record first but I believe it was also ~260 psi. Also, Installed vendor (CK Performance) Pan spacer and 700 filter.

 

What trans fluid are you running?

Some say to run Dexron 6 synthetic but others say to run non-synthetic Dexron

 

https://www.turbobuick.com/search/11...id&o=relevance

A little discussion on Tractor and other fluids threads with the Buick boys...

 

The shuttle shift between 2-3-2 is a common issue. You can play around with TV cable adjustment a little, sometimes that helps. You have to be very careful, loser I gotta the cable might solve one problem and create another (burnt clutches). The shuttle shift is the lesser of 2 evils in my opinion!

read this

https://www.turbobuick.com/threads/2...huttle.346779/

 

And another thread on this issue.

https://www.turbobuick.com/threads/2...t-hunt.401753/

 

And another



https://www.turbobuick.com/threads/2....346779/page-2

 

Thanks for the links, Matt. I never would have found that info (searching on the wrong keywords) since it doesn’t feel like a shift to me - particularly a shift involving 2nd (I don’t feel the ‘clunk’ when it shuttles like I do during a normal shift when the band applies). It feels more like just a gentle change in RPM. At first, I thought it might be the TCC shuttling, but I’ll assume it’s Shuttling between 2nd and 3rd since that is a documented issue, at least until I drive it more. Regardless, doesn’t seem like anyone can agree on a cause, let alone a solution. Definitely paranoid about loosening the TV cable too much, although with only slightly higher than stock power levels of my 350, I’m not too incredibly worried about burning out the clutches putting whatever miles on the vehicle before I store it. Thanks for all your help.

 

The 200R4 I built for my 455 power 87 cutlass would occasionally do it. I could never duplicate on command, just randomly it would do it. I never did eliminate it, just kinda band-aid it. I don’t have that car anymore, but I still have the drivetrain.

I had a line pressure gauge on the car to verify that the pressure didn’t go too low. I think 2 clicks looser eliminated most of the shuttle shift. The line pressure was still within the limits CK recommended.

 

Make sure it's not the lockup first. Just disable the lockup circuit for a test drive.
No matter what I do, my lockup still hunts when driving in the city.