I fear the worst! Help!
02-15-2006, 05:55 AM
#46
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this is only an issue with automatic transmissions
Consequently there is no flexplate to flex and somehow put pressure on the thrust bearing.
I believe there are cases of TBF failure in manuals but they are very rare and not caused by flexplate flexing.
Marton
02-15-2006, 08:19 AM
#47
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Brent,
Pull your oil filter as was mentioned previously and cut the tin can off: if you see nothing there or in the drained oil, it may be time to
. If copper and bearing metal shows, it is likely that the thrust bearing is being sacrificed - but not yet through to the block 
If there is a pile of aluminium shavings, well ... 
The first time I 'measured' crank end float, I did not have a dial gauge: instead, I clamped a nut to the bell housing that would allow a bolt to be turned in to touch the flywheel ( taking up the 'lash', or slack in the threads. Then, push the crank forward, and measure the difference with feeler gauges ... being careful to keep the same light pressure on the bolt. A solid rod would do, but it is easier to adjust a threaded reference point.
This should be accurate enough for your purposes ....
Pull your oil filter as was mentioned previously and cut the tin can off: if you see nothing there or in the drained oil, it may be time to
. If copper and bearing metal shows, it is likely that the thrust bearing is being sacrificed - but not yet through to the block If there is a pile of aluminium shavings, well ... The first time I 'measured' crank end float, I did not have a dial gauge: instead, I clamped a nut to the bell housing that would allow a bolt to be turned in to touch the flywheel ( taking up the 'lash', or slack in the threads. Then, push the crank forward, and measure the difference with feeler gauges ... being careful to keep the same light pressure on the bolt. A solid rod would do, but it is easier to adjust a threaded reference point.
This should be accurate enough for your purposes ....
02-15-2006, 09:15 AM
#48
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I'll check it today. I keep thinking "I know this didn't go out over night" in fact I don't think that I put enough miles on the car myself to do it. I must have been like this prior to my purchasing it so......... Why is it stalling after it warns? It cranks right back up now that I've taken out the flexplate tension. MAF?
OH........ the car no longer surges forward when I rev the engine in park!
OH........ the car no longer surges forward when I rev the engine in park!
02-15-2006, 10:04 AM
#49
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Another thing that happens when the engine is warmed up is that the A/T, convertor and fluid is warmed up, too. If it were me, I'd slide the coupler all the way back to rule out the drivetrain. I continue to be sceptical about TBF. The surging forward in park is not related to TBF. Another interesting test is to get the rear wheels off the ground when the car barely starts and see what the wheels are trying to do. From my memory from my 86.5 the wheels still want to turn even in park. A faulty torque convertor could leave the car 'engaged' even in park.
02-15-2006, 10:54 AM
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Originally Posted by 86_5Tiburon
Another thing that happens when the engine is warmed up is that the A/T, convertor and fluid is warmed up, too. If it were me, I'd slide the coupler all the way back to rule out the drivetrain. I continue to be sceptical about TBF. The surging forward in park is not related to TBF. Another interesting test is to get the rear wheels off the ground when the car barely starts and see what the wheels are trying to do. From my memory from my 86.5 the wheels still want to turn even in park. A faulty torque convertor could leave the car 'engaged' even in park.
02-15-2006, 01:29 PM
#51
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Originally Posted by 86_5Tiburon
Another thing that happens when the engine is warmed up is that the A/T, convertor and fluid is warmed up, too. If it were me, I'd slide the coupler all the way back to rule out the drivetrain. I continue to be sceptical about TBF. The surging forward in park is not related to TBF. Another interesting test is to get the rear wheels off the ground when the car barely starts and see what the wheels are trying to do. From my memory from my 86.5 the wheels still want to turn even in park. A faulty torque convertor could leave the car 'engaged' even in park.
02-15-2006, 01:50 PM
#52
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When you have the car up in the air and release the coupler, keep the shifter in park, release the parking brake and grab one of the wheels and see how much play you have (listen/feel). Do this with the otherside also. Additionally, pull the wheels in and out to check play as well. Then put the shifter in Neutral and do the same things, but also spin forward and then backwards. You should be able to tell if you have a final drive, tranny, TC or TT issue at this point. (I am assuming you know what should sound and feel correct)
02-15-2006, 03:30 PM
#53
Originally Posted by marton
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this is only an issue with automatic transmissions
Consequently there is no flexplate to flex and somehow put pressure on the thrust bearing.
I believe there are cases of TBF failure in manuals but they are very rare and not caused by flexplate flexing.
Marton
It's one of the reasons i like the OBs better, to be honest.
02-15-2006, 03:32 PM
#54
Originally Posted by 86_5Tiburon
Another thing that happens when the engine is warmed up is that the A/T, convertor and fluid is warmed up, too. If it were me, I'd slide the coupler all the way back to rule out the drivetrain. I continue to be sceptical about TBF. The surging forward in park is not related to TBF. Another interesting test is to get the rear wheels off the ground when the car barely starts and see what the wheels are trying to do. From my memory from my 86.5 the wheels still want to turn even in park. A faulty torque convertor could leave the car 'engaged' even in park.
I would consider that normal on a 928 or any other A/T equipped vehicle.
02-15-2006, 04:46 PM
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TBF failures are extremely rare with the 16v A/T cars. It's the 32v cars that mainly suffer from this issue.
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It's one of the reasons i like the OBs better, to be honest.
Me too, & no complex electronics, flappys, ABS & RDK & other sensors, &&&
Marton
81s
02-15-2006, 11:22 PM
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Update: Took the TT coupler loose from engine (very little resistance on the TT side when spun by hand). I tried to measure the flywheel play with a small metal ruler (I will have a dial indicator tomorrow) It looks like 1mm maybe less but I'll know better when I get a dial indicator.
Started the engine up and before it could get to temp. it died twice. When it dies it just flat dies! Like the key was turned off! Not gradual at all! I started trying things. I may have a bad TB but I'm not convinced yet that my engine dieing is caused by that. P.S. it starts right back up with no problem. Took off the supercharger, the oil filter, the oil adapter that sends oil to the supercharger, the air pipe from the SC to the MAF. It ran without stopping but not well. It idled low (500 rpms) when I gunned it and let it go the rpms dipped then recovered. Finally I took the 90 degree rubber boot off of the MAF (the one that the SC pipe hooks too) and restarted. It ran MUCH better pretty close to normal! and idled at 600rpms rather than 500. It seems like the problem is in the air flow. Could it be the MAF? What other sensors are monitored during idle? also I watched the air/fuel meter at idle it was pulsing (from lean just into rich then back to lean over and over)
Started the engine up and before it could get to temp. it died twice. When it dies it just flat dies! Like the key was turned off! Not gradual at all! I started trying things. I may have a bad TB but I'm not convinced yet that my engine dieing is caused by that. P.S. it starts right back up with no problem. Took off the supercharger, the oil filter, the oil adapter that sends oil to the supercharger, the air pipe from the SC to the MAF. It ran without stopping but not well. It idled low (500 rpms) when I gunned it and let it go the rpms dipped then recovered. Finally I took the 90 degree rubber boot off of the MAF (the one that the SC pipe hooks too) and restarted. It ran MUCH better pretty close to normal! and idled at 600rpms rather than 500. It seems like the problem is in the air flow. Could it be the MAF? What other sensors are monitored during idle? also I watched the air/fuel meter at idle it was pulsing (from lean just into rich then back to lean over and over)
02-16-2006, 12:22 AM
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Thanks Heinrich! The oil (synthetic) looked a little strange. I don't want to comment on it's appearance just yet because I was working under flouresent lights tonight and as you know it's VERY hard to get an accurate color when the light you are using is missing colors of the light spectrum. I saved the oil and will look at it tomorrow. I did poor the oil out of the filter through my hand and into a shallow tray. I didn't see/feel and metal particles.