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Looking for some guidance. I was having transmission issues, like grinding when shifting and popping out of 3rd. Took the trans off and found the pilot bearing in pieces (what was left), fused to the input shaft and put some nasty grooves in the input shaft and crank. Trans shop inspected the internals of the transmission and everything looks cherry so that's good. Have a new input shaft on the way, but was wondering if anyone had guidance on my options for fixing the crank outside of replacing it? Also, the pilot bearing only had around 5k on it. Any idea what causedit to fail so quickly? I have an ls7 clutch and ls2 flywheel installed. Thanks for the help.
if the transmission was pulled in by the bolts on last clutch install...that could have compromised the pilot bearing causing its quick failure
ideally the crank is not out of round now where pilot bearing goes and if just scored in a few places maybe just clean up the rough edges with some emery cloth and install a new bearing
Single must important factor here seems to be ignoring noise, usually if we find out what complain is about rite away mess can be avoided.
Another way to avoid the mess is doing the work yourself, seems like the last guy to install your clutch didn't bother to put a little bearing grease in there if he wasn't going to replace the pilot bearing.
I always jam more grease into any bearing before I install it.
There's two types of pilot bearings, one is just a bronze bushing I still put high heat wheel bearing grease in there cause it can't hurt anything.
The other is a needle bearing, these needles need grease or will make a mess, you don't want whole lot of grease in there but you need enough.
Sure you already know this but always change pilot bearing when you change clutch.
As far as bushings versus bearings, the transmission guy HIGHLY recommended putting in a bushing instead of a bearing. He remarked that he has replaced many input shafts due to pilot bearing failure and was a firm believer in bushings. After reading many debates on this forum, I understand there are people who believe in one or the other. I'm not saying either side is right or wrong, just seems there are pros and cons to using either a bushing or bearing, and after my experience I will have a bushing installed. As far as greasing the bushing,...he said DO NOT put any kind of grease on it. Apparently it messes up the function of the bushing somehow.
As far as the noise goes that's another story. While I was deployed I stored my car at a friends house. When I returned, he commented on how i needed to check on the transmission, so I took it for a test drive. I don't recall any remarkable noises, but that thing was grinding and popping out of gears. Guess he took it on a few too many joy rides? who knows. The pilot bearing was replaced after a new clutch install several months before I left.
Now I'm having the trans rebuilt with new synchros, input shaft, upgrading to bronze pads, bronze cup, and billet keys.
I however do need a new bellhousing if anyone has one i can buy
Just throwing that out there.
All is now well with the transmission. Everything is installed and smooth as it ever was.
I purchased a BYO rebuild kit and new bell housing from Hawks. Delivery was QUICK. Items arrived at the shop in 2 days. Very nice. Kit even came with an extra shift fork and snap rings. Currently the trans has just about new everything, to include input shaft, bronze pads, billet keys, bronze isolator cup, sitting behind an LS2/LS7 flywheel and clutch and MGW shifter.
The old bellhousing was cracked in a couple spots, including at one of the dowels. The owner of the shop said that the location of the cracks could have very likely thrown the alignment off just enough to cause the premature pilot bearing failure. Some of you out there surely would know better than I would.
I personally won't ever use a bushing again. This is what it looked like after 30k miles. I was having numerous issues, and a lot of it can point to this:
I guess they might be fine if you want to replace it at every oil change.
Hopefully my bushing will fare a little bit better than that, but only time will tell. After my old pilot bearing prematurely failed and destroying my input shaft, I took the advice of the transmission guy and went with the bushing.
Rust is from sitting outside
cracked at the dowel and on the other side as well
The old bellhousing was cracked in a couple spots, including at one of the dowels. The owner of the shop said that the location of the cracks could have very likely thrown the alignment off just enough to cause the premature pilot bearing failure. Some of you out there surely would know better than I would.
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Well in your case a failing bellhousing that was cracked/broken in areas, especially around the dowel hole would miss align the tranny and kill any Pilot bearing or bushing. resulting with damage to input shaft..maybe more from a bearing. Point is the "cause" had nothing to do with weather you used a bearing or bushing
Good you found the source of the problem...but it, to me, would have been visually obvious if the condition of your bell housing was what you described when the tranny was being installed previously. The bellhousing dowel holes and dowel pins in the block are there specifically to line up the bellhousing so tranny is then aligned properly when bolted in.
Well in your case a failing bellhousing that was cracked/broken in areas, especially around the dowel hole would miss align the tranny and kill any Pilot bearing or bushing. resulting with damage to input shaft..maybe more from a bearing. Point is the "cause" had nothing to do with weather you used a bearing or bushing
Good you found the source of the problem...but it, to me, would have been visually obvious if the condition of your bell housing was what you described when the tranny was being installed previously. The bellhousing dowel holes and dowel pins in the block are there specifically to line up the bellhousing so tranny is then aligned properly when bolted in.
I agree with you completely and most probably the problem stemmed from the actual bellhousing and not the pilot bearing. Regardless, I took my guidance from the transmission guy, who justified the use of a bushing because it was a softer metal and less likely to do damage to any other parts in the event of a failure.
While Tremec specks a bearing vs bushing, which is why GM put them in T56 cars, some do run the bushing. Yes bushing is softer metal than input shaft so it will typically not damage it.
FWIW I have run a bearing for 10 years now. I changed it when I put in my Twin last year. Old one was fine but since I was in there I just replaced it.
While Tremec specks a bearing vs bushing, which is why GM put them in T56 cars, some do run the bushing. Yes bushing is softer metal than input shaft so it will typically not damage it.
FWIW I have run a bearing for 10 years now. I changed it when I put in my Twin last year. Old one was fine but since I was in there I just replaced it.
Good info. When the time comes for replacing the bushing I might switch back over to the bearing. Hopefully that time won't be any day soon though. If any new events take place regarding the transmission, I'll be sure to update this thread for everyone's SA. Spending this extra time and money on the transmission is cutting into my heads and cam fund
Make sure you dial in the bell housing. I'm installing a T-56 Magnum with a Quick Time 8020 bell housing.. According to Quick Time/Lakewood, I have to dial in the bell housing to the front transmission plate.
Make sure you dial in the bell housing. I'm installing a T-56 Magnum with a Quick Time 8020 bell housing.. According to Quick Time/Lakewood, I have to dial in the bell housing to the front transmission plate.
I was doing some searching around on the forum for dialing in a stock bellhousing vs aftermarket. Seems like the stock is pretty true, but perhaps someone with experience could chime in
10-02-2014, 10:24 PM
T56 pilot bearing disaster 
