Dan,
I, and others here, have used both bearing and bushing. I, and also others, have seen the bearings fail. When they do, they become a chewed up mess-----------------------AND, can cause damage to the nose of the input shaft of the tranny!!!! But, when the bushing becomes worn, the hole in it simply becomes enlarged. IF, just IF, you do use the bearing, GREASE it liberally!!!!!!
I have long ago quit using the bearing. I am a hard core believer in using the bushing----------------------GET A GOOD BRONZE ONE RATHER THAN A STEEL ONE. NAPA usually has the bronze bushings. Also, I think the BCA bushings are the bronze versions.
Now, how do you tell whether or not a bearing is OK after lots of miles? You gotta pull the tranny/clutch and inspect it. If its OK, grease it good again. If it is bad, then you will see why I (and others) use the bushing instead.

 

Does that apply on all transmissions? TKO's?

 

Thanks Tom, that's the answer I was looking for. I'm gonna return the bearing & go to napa for a ushing.

 

Tremec recommends the pilot bearing instead of the bushings. I use the pilot bearing in my TKO600 in in my Camaro. The specs for dialing in the bellhousing on a Tremec is tighter, .005 than a Muncie, also. I usually like to use what the manufacturer recommends, that way if there are any warranty issues, they can not use that as an excuse for the problem you are having.

Mike

 

I am still going to check the bell but I bought the McLeod scatter shield & they claim that it is well within the needed spec so no adjustment is needed as long the block has not been line bored. I also bought a Mark Williams 1350 slip yoke for a little added protection.....

 

just like always Tom is pointing you in the correct direction ... I woundn't install a pilot bearing ... Unless the owner Insisted on it & signed a waiver saying it !@
I hate to disagree with DZ ... but you did say -can- cause damage -if- it fails
I'm more inclined to say IT will Fail & cause damage !! BTDT :sad:

 

Thats why I was leery....& asked the question first

 

less moving parts= less problems

 

Hi Dan,word of caution,it sems that some of the tolerances have slipped on the stock piolot busings mfg these days.

When i rbly my 396 in 2001 with m20 the stock pilot bushings i bought would all fit very Tightly over trans input shaft prior to installing them in the crank.

I bought 4-5 dif stock pilot bushings from doorman(local auto parts stores),Zoom,Hays,summit,jegs hopeing to get one that didnt fit too tight over input shaft or in crank but they were all a very tight fit in both areas but i had run out of optionts. i could either run the roller bearing pilot bushing that has a reap of comming appart or install one of the what i thought was too tight stock pilot bushings i already bought with no more new stock avail in my area or through mail order for me to try.

Then (against my better judgement) i installed 1 of the new stock pilot bushings in the crank (which was hard to get seated in crank/was very tight fit),then input shaft would not fit into the bushing any more and the new pilot bushing was now stuck in the crank. I think the bushing being too tight in the crank closed up the input shaft hole a smidge then the input shaft would not fit after that. I was screwed at that point,trans would not install and bushing would not come out even with removal tool or the old grease in the bushing then hammering a wooden dowel into bushing to force it out,would not budge.

The crank was stock,never machined and i had the motor out of car 2x back in the late 70's and changed the pilot bushing both times with none of these fitment issues on input shaft or after new bushings were installed in the crank either.

Now all the sudden 20yrs+ later those same type stock pilot bushings are very tight on input shaft prior to installing in the crank and they are almost too big to fit in crank but do go in with a fair amount of force but then the hole for the input shaft closes up just enough due to tight fit in crank to then stop the input shaft from going in. I think this is due to whoever make these bushings is mfg them with the tollerance just a tad off for inside & outside diameters that can happen when the same item is made by mult mfgs over many yrs and the mfg specs seem to have drifted just a tad from the orginals over time.

I ended up having to thread a 5/8 " cap bolt into the pilot bushing so it would bottom out in the crank and force the bushing out and as i kept threading it in which worked great & took only approx 2-3 mins to do once i started,great trick i got from where else,TEAM CHEVELLE !!!!.

Since i could not find any new stock pilot bushings that fit correctly I attached one of the new pilot bushings i had to a drill in a vise(for even removal of material) and cranked it up full speed. Then i used some 400 grit paper to help against the outside & then inside the bushing to slowly wear/sand away enough material to get better fit over input shaft & in crank too. To be safe I used some 800 grit to smooth/polish the input shaft hole in bushing after i was done removing material with the 400 grit. I know this wasnt a very precise way to do this but i was up against a tight time limit and had to get the car together & running due to loosing garage space to work on it so i didnt have the time to take the pilot busning to a machine shop to have is poperly turned down a smidge for better fit.

After that the bushing installed snug (but not too tight) in crank & also the input shaft went fine into the bushing when trans was installed and i have had no problems since.

In heinsite i wished i had never botherd to change the bushing that looked & worked fine for the past 20+ yrs that was in the motor when i rbly it and should have just left it there. If your pilot bushing looks fine and the input shaft is not sloppy in it just keep it and dont bother changing it IMHO.

But if you must change it make sure to test try your new bushing over the trans input shaft then try putting trans input shaft (or clutch aln tool) into the bushing again after bushing is installed in crank before you install the bellhosuing to ensure it still fits ok to avoid going through all the hastle i had over a $5 bushing that really didnt need to be replaced in the 1st place.

Scott

 

what If I dont change it when I change the clutch & flywheel?

 

Dan,just as long as the pilot bushing currently in your motor looks ok and the trans input shaft or clutch aln tool fits fairly snugly in the bushing with out too much slop you should be ok.

It was a real PIA when i went through all that crap i mentioned above with the stock pilot bushings made today,they all sucked in quality control which caused me alot of wasted time,effort,and a few $ too.

What happened to your current clutch,did all the xtra power found from that new voodoo cam take a toll on it?

Scott

 

What happened to your current clutch,did all the xtra power found from that new voodoo cam take a toll on it?Scott

Scot, The current clutch is fine but has a really stiff pedal feel to it & since I got the after after it had been sitting since the late 70's, I figured I'd better pull it before it goes.
I picked the centerforce dual friction setup & flywheel due to the lower pedal feel & high holding power, because of my health issues AND the power this thing is making.
I only want to do this once so I am going for a little overkill.
It is also part of my "fixing the all mechanicals" plan before it goes to the bodyshop someday. The winters projects are : complete front end suspension rebuild, new clutch/flywheel & getting the cowl induction system to work.

 

Dan borrow a dial bore gauge an measure the I.D. of the bushing
then measure the O.D. on the input shaft
I recommend replacement at .010 or more
an 98% of the time they are larger, it is a wear part & meant to be replaced
the more slop you allow in the input shaft the more stress you put on the front bearing in the trans ...

 

good idea, I have a set of digital calipers so I will measure & see what I get.