Forward gear shims

[Matthew A.]

According to the HSG number stamped on the lower unit housing [assuming the location of the stamped number is under the oil fill plug] the foward gear should have a minimum of .008" of shim material under the forward gears roller bearing "outer race". Upon pulling the "outer race" from the lower unit, to my surprise, there was no shims under the outer race. There were however, shims located under the foward gears roller bearings "inner race" between the bearing and the gear itself. None of the manuals I have read mention the possibility of finding shim material under the inner race sandwhiched between the gear and the bearing. The forward gear does not have a location where a number or letter has been stamped. There is however a raised mark on the side of the gear that appears to resemmble the number 5 or possibly the letter S. Because of the stamp code on the housing dictates there must be a minimum of .008" of shim material under the "outer race" regardless of the code stamped on the gear, and there were no shims under the "outer race"; and because there was shim material where no manuals say there maybe shims, I am unclear on how to determine whether or not any shim material should be used and where those shims need to be placed. Any one have any ideas on what to do and possibly how to do it? Also, the manual says the center bearing carriers needle bearing is not replaceable and the carrier w/bearing can only be had as one unit. I have a new torrington needle bearing that the carrier requires. Is there a specific reason why I cannot or should not press out the old bearing and install the new one I have and must replace both carrier and bearing as one unit?

 

[Frank Acampora]

Re: Forward gear shims

Roller bearings are manufactured to such close tolerances, that it makes no difference whether the shims are between the gear and the inner race or under the outer race. Either will positively locate the forward gear with relation to the pinion. Now, it's been a long time, but I seem to remember in the Intertech manual that the shims were located between the gear and inner. Perhaps your manual has a misprint?

The factory wants to ensure that the reverse gear and bearing assembly falls within tolerance so they only sell it as a unit. They take the position that if one bearing is bad so must be the others. If the other bearings and thrust washer are indeed not worn, then you will do no harm by pressing in your Torrington needle bearing. The thrust bearing and thrust washer locate the gear with relation to the pinion and are the critical ones. And even those are standard size so you could buy them from a bearing supply house.

 

[Matthew A.]

Re: Forward gear shims

Hi Frank,
Thank you for the information regarding the forward gear shims...not knowing anything about the shims being between the gear and bearing was buggin the heck out me.
Regarding the center bearing carrier and it's needle bearing. To make certain I understand you correctly, the factory's reason behind wanting to replace the center bearing carrier w/bearing as one unit instead of pressing out the old bearing and replacing it with a new one has to do with for the most part...if so much needs to be replaced...replace everything?
Now that I have the information regarding the numbers stamped on the forward gears outer bearing race I can finally order the roller bearing w/race. At the time when I ordered all the needle bearings and the driveshaft roller bearing/race I did not order the thrust bearing nor it's spacer since there was no information either stamped or printed anywhere on the bearing. After doing a little research on Timken's website and the website of the company that is supplying me the bearings, come to find out Timken only manufactures one thrust bearing with it's dimensions. And, only lists three different thickness's of spacers. Two of which I can defineately rule out.
Now to find a shop that has the neccessary equipment to install needle bearings correctly. Granted the needle bearins only cost 8 or 9 bucks. Two shops I went to have them install the them knew nothing about 15 degree bevels on the mandrel where it contacts the bearing housing nor of keeping the needle pins aligned while installing the bearing. Granted, I don't either. But I do know that Timken states installing them in any other manner almost always results in ruining the bearing housing. Perhaps my concern is unwarranted.