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88 Twin cam support Bearing wear

Dineh

New Member
Just join George's Garage hope to gain knowledge and understanding regarding my recently purchased 01 Dyna Wide Glide. Presently working on Cam tensioner replacement ie. Twin cam 88 stock engine. Question how do I determine if two cam support Roller and needle bearings are excessively worn? The cam riding on roller bearings will fall out of the bearing if I remove inner drive chain. Is this normal? I have no way of measuring bearing specs or proper fit. Please help.
 
I think you'll find that replacing the inner cam bearings when you do the tensioner upgrade is pretty standard. By doing so you'll have the peace of mind knowing you won't have a bearing problem down the line.
 
The OEM inner cam bearings should be replaced; they are not full compliment bearings like the Torrington/Timken B148s.
http://www.bigboyzheadporting.com/showthread.php?t=88

If you just want to replace the tensioner shoes, there are ways to do that without removing the cams from the plate but a special tool is required to roll back the inner shoe and remove it; some YouTube videos on that tool. Otherwise, the cams must be removed to replace the tensioners. There is a YouTube video of a rocket scientist that thought he could remove the tensioner without removing the cams and it is a very entertaining video if you want a few laughs.

The outer bearings need not be replaced unless they are pressed out of the bearing bores or pressed off the cams. The bearing that fell out need not be replaced if it has not been pressed off the cam; it will "fall" back into the bore with the cam. Apply some Loctite 660 to the bearing bore surface; a thin coat will do. Push the bearing/cam assembly back into the bore; you will have to align the inner gears and push both inner bearings into their respective bores together. If the other bearing is undisturbed, no need to replace it either. Google the "freezer/oven" or "heat/freeze" method for the R/R of the cams (with bearings attached); works every time and no special tools required. A Brit, Harley Hog, had a website with a complete video of the heat/freeze method but the MoCo shut him down a few years back. Pretty basic, freeze the outer bearings overnight; heat the cam plate in a 300* oven for about 20-30 minutes and drop the frozen bearings into the cam plate. Remove the inspection plug at the top of the cam plate before the oven; is has a rubber oring. Cams can be installed in the cam plate/bearings the same way; heat the cam plate, with bearings installed; freez cams overnight. Mock up the install setup first as you will need to have the cam plate level and secure; don't want it moving around. Install the inner chain; align the timing marks, and drop the cams into the bearing bores. You only get one shot at this as the cams will absorb the heat from the bearings pretty quick. Have done this plenty of times before I bought a small press. Only other way to do this will require a small press to press the bearings onto the cams and press the cam bearing assembly into the cam plate; should be able to find a YouTube video of the process.

You should have the service manual for your model. You will need a bearing puller to remove the inner cam bearings. Auto Zone used to rent a blind hole puller set which included the correct collet for the TC inner cam bearings. You can tap in the new inner cam bearings with a take off cam but as a one time fix but if you don't have one, George's Garage has the tool to remove and install the inner cam bearings.

If you haven't purchased tensioner shoes yet, don't bother to replace with OEM, replace with CYCO tensioners; you will need the CYCO tool to install the shoes onto the OEM holders.
http://twincamtensioner.com/

Read up on oil pump alignment before reassembly.
 
Welcome from So. Texas. Dolt has you pretty well covered for the process. As usual, a very nice write up from Dolt.
tourbox
 
For the OP or anyone else interested I have found and attached a .pdf file (from Harley Hog's website before it was shut down) of a step by step cam install on an early model wherein the heat/freeze method is used and a bearing puller setup is used in lieu of a press. Very detailed and documented process; there is sufficient information included to address the OP's questions/issues.;)
 

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  • 88 cam install.pdf
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I think you'll find that replacing the inner cam bearings when you do the tensioner upgrade is pretty standard. By doing so you'll have the peace of mind knowing you won't have a bearing problem down the line.
Thanks for the info re cam bearings I will comply ride on.....
 
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