Engine/Transmission (1994 - 1998) Nv 4500 sticking in 4th, thrust bearing grenaded

[SRadke]

98 model 12 valve. NV4500, about 25k on new bearings, syncros and mainshaft. Stuck in 4th gear three times so I pull it to find the flat back on the thrust bearing in a dozen pieces. Apparently these little pieces can get cocked sideways in there and prevent the shifter cog from sliding back into neutral after it's in gear. Any idea what would cause the bearing to go? Did I get the endplay too tight when I assembled it the last time? Have you seen anything like this? Any ideas appreciated.



-Scott

 

[kentdiesel]

Hello,

Did you measure the mainshaft endplay with a dial indicator the way the factory service manual shows?

Should of been . 002 to . 006 (inch) endplay.

I set mine at . 001 and have had no trouble after approx. 30,000 miles

Could it of had to much endplay and beat the bearing apart?

Did it run low on oil?

I know you want answers instead of questions but maybe these will help you figure out what happened.



Kent

 

[SRadke]

I had the endplay set at . 002" - . 003". It did not run low on oil and endplay wasn't a prob until the washer on the back of the thrust bearing gave up.



I put it back together this evening with a new imput shaft bearing and thrust bearing. The mains were questionable but given the circumstances we're running them. Best explanation I can find was evidence that the bellhousing was not properly aligned on the dowels. One of them had been forced in by the clamp force of the bolts and appeared to have been nearly 1/8" offcenter. Being out of alignment from the pilot bearing though the imput and mainshaft could account for the carnage.



It's not my style to force things but I guess the blame is mine as it was my project. I need to be more carefull who I ask to give me a hand put these things back together. Live and learn.



-Scott