|
Re: thrust bearing issues
[Re: TheOtherDodge]
#1031943
07/14/11 12:07 PM
07/14/11 12:07 PM
|
Joined: Jan 2003
Posts: 17,840
S.E. Michigan
ZIPPY
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 17,840
S.E. Michigan
|
Was it mocked up without the crank, but with the bearings to make sure the thrust surface(s) line up squarely (comparing upper to lower)?
Was the main cap just torqued down, or was the thrust bearing seated first? (referring to forcing the crank forward in the block during torque down)
Either of these can cause an oiling issue. If the bearing shell thrust surfaces are not square with each other, the oil film gets scraped off the thrust surface....
Just throwing a 'maybe' out there
Rich H.
Esse Quam Videri
|
|
|
Re: thrust bearing issues
[Re: TheOtherDodge]
#1031945
07/14/11 01:19 PM
07/14/11 01:19 PM
|
Joined: Jan 2003
Posts: 17,840
S.E. Michigan
ZIPPY
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 17,840
S.E. Michigan
|
Quote:
Zippy, I did not mock up the bearings to check alignment. I did set thrust after final torque, which I thought was the way you are supposed to do it.
I was taught to set thrust/force the crank forward more during torquedown, rather than after.
I can't claim that's perfect info...but that's what the instructors taught me in '88 or whatever it was. It may be flawed somehow for all I know.
Ex: if final torque is 90, then go about 30, set thrust. Do the other caps to the same torque. Verify end play/thrust. Then 60, set thrust again, do the other caps, check the gauge. Then 90, same routine.
Could be converter, but prob. not with that low of boost? 
Rich H.
Esse Quam Videri
|
|
|
Re: thrust bearing issues
[Re: TheOtherDodge]
#1031946
07/14/11 01:47 PM
07/14/11 01:47 PM
|
Joined: Aug 2003
Posts: 43,116
Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,116
Bend,OR USA
|
Quote:
Zippy, I did not mock up the bearings to check alignment. I did set thrust after final torque, which I thought was the way you are supposed to do it.
How can you set the thrust after all of the main bolts are torque to spec? I torque #1,2,4, and 5 to the final torque specs, it varys with motors. I torque #3 to 20 to 30 Ft lbs and then check the end play, thrust measurement. If within spec I tighten # 3 to final torque specs. and check it again, if it is not within, to little, I use a dead blow hammer and tap (whack it hard  ) the crank back and forth to settle the bearings shells in the caps and center them on the main caps, I then check it again  If it is okay then I tighten it down and recheck when tight, if not within specs. it is time to figure out why 
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: thrust bearing issues
[Re: TheOtherDodge]
#1031948
07/14/11 02:20 PM
07/14/11 02:20 PM
|
Joined: Feb 2004
Posts: 4,501
Gainesville,FL
goldmember
master
|
master
Joined: Feb 2004
Posts: 4,501
Gainesville,FL
|
Quote:
"How can you set the thrust after all of the main bolts are torque to spec? "
Why can't you? The crank better not be that tight where you can't set the thrust!
You have to set the cap correctly and I don't see how you'd do that with the cap torqued tight to the register. The cap should have enough clearance between the bolt/studs to allow the cap to be aligned with the block,making the bearing aligment correct.
|
|
|
Re: thrust bearing issues
[Re: TheOtherDodge]
#1031950
07/14/11 02:57 PM
07/14/11 02:57 PM
|
Joined: Jan 2003
Posts: 11,707
Portage,michigan
B3422W5
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 11,707
Portage,michigan
|
I had thrust bearing issues with my old 422 smallblock motor. The new owner of the car had the motor freshened, and the 727 freshened as well. The guy who is going through the trans told him he thought the problem with the thrust bearing was because of the line pressure the trans was using( 160), as the transbrake valve body was a Griner and as far as i know is supposed to be set there( the trans i had built by JPT, a long standing expert in performance automatics) i kinda doubt that this guy is correct about the 160 pressure being to high and being the cause. He told the new car owner the pressure should be about 60  Anyhow, i am unsure what the resolution is or will be.
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight
418 BPE factory replacement headed stroker, 565 lift solid cam
Best so far, 10.40 @127 1/4
1.41 best 60 foot
6.60 at 103.90 1/8
|
|
|
Re: thrust bearing issues
[Re: TheOtherDodge]
#1031954
07/15/11 06:08 PM
07/15/11 06:08 PM
|
Joined: Jan 2003
Posts: 25,743
Rio Linda, CA
John_Kunkel
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 25,743
Rio Linda, CA
|
Transmission line pressure doesn't put pressure directly on the crank but converter pressure does....under normal circumstances the converter pressure is much lower than line pressure.
But, in rare cases, the transmission reaction shaft can spin in its support and shut off the outflow of line pressure from the converter, when this happens the converter pressure regulator valve doesn't function and converter pressure is the same as line pressure.
The INTERNET, the MISinformation superhighway
|
|
|
Re: thrust bearing issues
[Re: John_Kunkel]
#1031955
07/15/11 06:25 PM
07/15/11 06:25 PM
|
Joined: Aug 2006
Posts: 114
Crossville,TN
526ciduster
member
|
member
Joined: Aug 2006
Posts: 114
Crossville,TN
|
When you get it apart look at the back of the converter and see if it has hit the crank bolts. I had two motors do this and it killed the thrust in both. One turbo car and one procharged car. We had a na car hit too but caught it before the thrust was damaged.
this may not be your problem but is worth checking into.
Outlaw 10.5
526ci, F3R procharged tfx hemi, Big Stuff 3
PTP RACING
|
|
|
|
|
Probally causing your problem 
I have had to use harden head bolt washers bewtween the flexplate and the converter lugs to avoid prelaoding tension from the converter to the crankshaft, cheap imported cranksahfts 
I'm guilty of using them 
Cab had the right idea about oil problem. The thrust bearing problem is either a bent crank or improper alignment of the main caps. A crank may feel free when you spin it in a new build. Put a lot of pressure on the thrust and any mis-alignment will break up the pressure film of the oil-result-bearing material all over pan. Any race engine must be align honed by good machine shop.