LT4 - input shaft bearing
Thread Starter
6th Gear
Joined: Nov 2019
Posts: 6
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LT4 - input shaft bearing
Pretty sure I have early stage of input shaft bearing failure. 48k miles. Without getting into all diagnosis details, has anyone had this replaced? Curious as to cost. Will certainly get issue verified, but just kind of wanting rough idea. Thanks in advance.
Instructor
Joined: Feb 2007
Posts: 132
Likes: 3
From: CRYSTAL RIVER FL.
If you are referring to the pilot bearing (bushing) in the crank shaft, it makes a slight growling sound. Throw out bearing makes a grinding sound with the clutch out. Will quiet down when the clutch is depressed. Use the original Oilite bushing and don't lube it, Don't use the roller bearing type. They don't hold up. When I replaced my clutch I found mine was wallowed out. Oval shaped.
Dave.
Dave.
Le Mans Master
Joined: Aug 2015
Posts: 6,119
Likes: 1,994
From: St. Charles MO
I agree with everything DAVECAD2.0 said. However, I think the OP is actually talking about the bearing on the input shaft of the transmission. I think it's pretty major surgery, requiring the case to be split open. You can get the input shaft seal replaced fairly easily if you have the transmission out of the car, but the bearing itself appears to be way inside the case and it's pressed onto the input shaft. I don't know how you could pull it and install a new one without removing the input shaft from the case. So the best thing here is really good diagnosis before paying someone to do all that work. It may still require removing the trans from the car to diagnose, but once it's out you can check shaft play and maybe some other parameters that will tell you if it's really the input shaft or not. By far your best reference will be ZF Doc. I'd email him and see what he thinks you should check.
