Thrust Surface Worn Again Why?

[BobbyBuick]

Well , had a oil blowby problem.in looking for the cause I pulled the pan last nite. I found the thrust surface goin south again after only about 40 passes.Last time I had it down I had the convertor gone over with a bigger anti ballooning plate.The builder insisted it was NOT ballooned.however he went clear through it. Also I made some modifications to the new bearing itself by drilling out the hole to .250 and drilling a side chamfered hole into the surface it was .0625 i think.
I spoke with TCI today they made my brake and they said that NORMAL line pressure is 180-200 PSI All the time and thats normal (dont know what mine is yet)and not a problem.Im running a 400 turbo and for those of you who know me I do launch the car at high boost levels( about 15 psi).anyway I dont know the extent of the damage yet as Im
pulling the motor and tranny .Just looking for possible causes and possible solutions.Thanks in advance
Bob B-BUICK Slusser

 

[Chuck Leeper]

THRUST PROBS??

Bobby, there's a fix for that. It involves a , I believe, .070, orifice in the converter feed circuit. I had the same problem and got the fix from Don Wang.
The converter is not balooning. The converter is being forced off the stator support by the trans psi. Thus the crank is being shoved into the thrust brg and it's down hill from there!!

Call or e-mail Don to be sure about the size of the restriction, as it's been a while since I did mine, and I have CRS!!

HTH,

Chuck

 

[1320n10]

I will let you know as soon as i get mine out how the thrust looks. Saturday afternoon i had a vacume line blow off at about 1000' and now there is a death knock in the motor. I ran the latest no maf chip and ran 103 in the 1/8 with 4 psi less than at moroco and in 85 degree weather. I did also put a .82 garett housing on.What sucks is the head gaskets are sealed better than ever.

 

[Steve Wood]

Damn, Walt, you were moving!

 

[BobbyBuick]

CHUCK,THANK YOU ,THANK YOU.I know it had to be something like that.
And WALT Same here heads were sealed better than ever! sorry to here about your luck.I know youve been trying to get ahold of me .my father inlaw passed away on fathers day and we have been not home at all. I think you and Steve better listen up on this as I know everything went togather correct on my motor.I sincerely think the line pressure is killing it.I will be calling you Chuck .I need to get ahold of DON WANG anyone have a # you can email me please do thanks again guys

 

[Chuck Leeper]

Don wang's #

Bob, the number is 619-258-4240. It's DRW tranmissions
Santee, CA. Near San Diego.

Back to welding a roll bar

 

[Otto J]

keep me updated on htis problem, is there an orifice for the 2004r to keep this from happening?
Otto

 

[quickt]

Walt what head gaskets did you go with? Bob wish I could help with the 400 problem but I run 300psi line and also leave at 25+ boost when the track will hold and have not had that problem. I run a 200. Not sure what the difference if any there would be with the line pressures of 400 v/s 2004R and the converter.

 

[BobbyBuick]

I think he is running the same as Jason and I .the shimm sandwitch.Jay Carter is the founder to my understanding with GE. 1200 silicone+ 2 sets of 85 shimm gaskets

 

[1320n10]

Bob i did not use the shims. I used the loc wires. I already had them and cal hartline gave me some pointers on how to make them work. I will let you know as soon as i get the pan off how things look.

 

[ijames]

The problem is not the main line pressure in the valve body, it's the back pressure in the line to the cooler. The fluid goes through the converter and then to the cooler and then on to the bearings/etc., and if the cooler is too restrictive or there is too much flow after raising the main line pressure then this back pressure presses the converter too hard on the thrust. The 400 converter has a bigger neck and so is a bigger piston, pushing harder than the 2004r converter for the same back pressure. There was a thread on this in the transmission forum a month ago, with a link to an article giving some pressure recommendations for the 400.

[Okay, found it] Goto http://www.turbobuick.com/forums/showthread.php?s=&threadid=41900

If you know the thrust dimensions of a Chevy big block and our v6 so we can compare the areas that would be great. Thanks.

 

[BobbyBuick]

OK,Im not a tranny expert or have I tried this yet but here is what Ive learned since last weekend.after reading an article by ATRA about thrust failure I found that the the thrust surface on a big block chevy can withstand 210 pounds.now the sq in of the convertor hub x the line pressure = force and after I spoke with tci they said the line pressure all the time is 180-200psi non modulated on a 200 its modulated with the detent.now if you do the math thats somewhere around 318-422 pounds.Even on the low side its twice as high as it shoud be. I spoke with Chuck Leeper and he said it cost him a few cranks for he got ahold of Don Wang.After making the Mod Don sugested Chuck has had no more problems with the thrust I mean SOO I called Don ,he said you need 40 psi at the cooler line and all the fluid the convertor needs is 1 qt in 20 seconds thats a rule of thumb they go by.now for the mod. On the pump cover their is a passage straight down from the stator that runs at an angle up by the pressure regulater.at the opening by the regulater tap the passage with a 1/8"pipe tap and drill a 7/64 hole in the pipe plug.this mod will releave the amout of fluid that is pushing the convertor off the stator support.Now I havnt done this yet .and if a tranny guru can help out here Im open to listen .I am interested in this metalizing as I may be past the over sized bearing Thanks Bob Slusser