Talks of moving this to HD engines-TC sub forum, and making it easier to read. This could be the first post, maybe making easier to read. This thread was an offshoot of electrical question on 2000s for a bike a guy had inherited. I brought this up in case he didn't know about it. It was a long time ago.


Per recent discussions, a reminder that 1999s and some 2000s twin cams had issues with the rear cam bearing. You may be able to look up date and VIN.

Evos had gears, TC have chains. TCs were experiencing failures of the rear bearing, in the plate, not the needle bearings in the block, due to side loading of chains. There was threats of class action law suits, but I don't think it went anywhere. Probably old threads here about it.

Originally twin cam bad ball bearings for both cams. They then switched to roller in rear cam. But if you went to gears you went with both ball.

When ordering kits you need to specify chain or gear. drive
chains ball and roller& ball for chain. Examples of the kits.
https://www.jpcycles.com/product/ss-...AaAmWIEALw_wcB

with gears both ball bearings
https://www.denniskirk.com/s-and-s-c...UaAuXfEALw_wcB
Subject: Rear Cam Bearings on 1999 and early model Twin Cam 88 and Twin Cam 88B motors.

On December 14, 1999 a running change was made in the design and production of the rear cam bearing in Twin Cam 88 and Twin Cam 88B engines. The change replaced the ball bearing style bearing in the rear cam with tapered roller bearings. The Motor Company is aware of the publicity this change has received and the concern some customers may have with the performance of cam bearings.

In order to ensure our customers' satisfaction, the Motor Company extended a 5 year/50,000 mile warranty on the rear cam bearings to owners of certain 1999 and 2000 vintage Twin Cam 88 and 88B motorcycles. The affected motorcycles have ball bearing style bearings in the rear cam and were manufactured between July 1998 and December 14, 1999. This offer reflects the Motor Company's confidence in the product as well as its willingness to go beyond the normal one-year warranty in order to ensure our customers' satisfaction. Under the terms of this warranty, any failure of the rear cam bearing during the extended warranty period will be covered by the Motor Company at no cost to the customer when the service is provided by an authorized Harley-Davidson dealership.

Any questions about which bikes are affected by this warranty or any questions or problems related to your specific bike can be answered by calling the Harley-Davidson Customer Service Department at 1-414-343-4056.

 

Here is what my research/experience has shown me...FYI...

From the advent of the 88" Twin Cam until the 2006 Dynas, and 2007 all other models, the inner cam bearings were OEM #9198. They were the INA brand, caged needle bearings B-148.

They switched in '06 Dynas, and '07 all other models, to OEM inner cam bearings #9215. They too were INA Brand, caged needle bearings, but in a slightly larger size, B-168.

They were changed because the size of the cams changed, so they needed a bigger bearing. Same design, they were still caged bearings.

The aftermarket led by Torrington, later bought out by Koyo, offered captive needle bearings. They are a better, more reliable design. Most shops and home wrenches used these bearings as an update due to the inner cam bearing failures, in place of both OEM bearings B-148 & B-168....

To my knowledge, for the M8 engines, the OEM inner cam bearing is still an INA caged bearing, #9215....

 

I did not start this thread, I was hoping to help a guy who inherited a 2000.
Evos had gears, TC have chains. They were experience failues of the rear bearing, in the plate, not the needle bearings in the block, due to side loading of chains. There was threats of class action law suits, but I don't think it went anywhere. Probably old threads here about it.

Orinally twin cam bad ball bearings for both cams. They then switched to roller in rear cam. But if you went to gears you went with both ball. Maybe I got ball and roller backwards.

So harley, I believe mid year 2000 changed the rear cam bearing.

When ordering kits you need to specify chain or gear. drive


chains ball and roller geara
https://www.jpcycles.com/product/ss-...AaAmWIEALw_wcB

with gears both ball bearings
https://www.denniskirk.com/s-and-s-c...UaAuXfEALw_wcB

 

Subject: Rear Cam Bearings on 1999 and early model Twin Cam 88 and Twin Cam 88B motors.

On December 14, 1999 a running change was made in the design and production of the rear cam bearing in Twin Cam 88 and Twin Cam 88B engines. The change replaced the ball bearing style bearing in the rear cam with tapered roller bearings. The Motor Company is aware of the publicity this change has received and the concern some customers may have with the performance of cam bearings.

In order to ensure our customers' satisfaction, the Motor Company extended a 5 year/50,000 mile warranty on the rear cam bearings to owners of certain 1999 and 2000 vintage Twin Cam 88 and 88B motorcycles. The affected motorcycles have ball bearing style bearings in the rear cam and were manufactured between July 1998 and December 14, 1999. This offer reflects the Motor Company's confidence in the product as well as its willingness to go beyond the normal one-year warranty in order to ensure our customers' satisfaction. Under the terms of this warranty, any failure of the rear cam bearing during the extended warranty period will be covered by the Motor Company at no cost to the customer when the service is provided by an authorized Harley-Davidson dealership.

Any questions about which bikes are affected by this warranty or any questions or problems related to your specific bike can be answered by calling the Harley-Davidson Customer Service Department at 1-414-343-4056.

 

Also this is no unique to dynas so I am not sure why the mod moved it to dyna section. It should be a general engine section.

 

Rounders, I owe you an apology....

I thought by "rear cam bearings" you were referring to the "inner cam bearings"...... That's why what you said made no sense to me... That was my mistake... I see now what you were referring to, and that your info was correct....

After reading your additional info, I realized you were talking about the cam plate ball bearing #8990A, used for both cams in the cam plate on the very early Twin Cam engines.

The MoCo replaced the rear cam's, cam plate ball bearing #8990A to a #8983 bearing, leaving the #8990A ball bearing in the cam plate for the front cam.

I must admit, I totally forgot about that issue/change until I read your additional info..

I appreciate the corrrection...