Transmission Rebuild-27 T

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration
Model T Ford Forum: Forum 2011: Transmission Rebuild-27 T
Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Wilson on Saturday, July 09, 2011 - 11:12 am:

I know there have been several threads on rebuilding Model T transmissions but I have not seen this issue covered. I have installed new bushings along with replacing a couple of scored drums (Low and reverse) with better used ones.I can't seem to get adequate clearance for the clutch hub. I am using three new thrust washers but when I put the drum on I have to really force it down to get the set screw in and end up with 0 clearance at the thrust washers. Two questions:
1-Do I have to face the triple gear bushings down to the .006 to .010 recommended in the transmission book published by MTFCA and could this be contributing to my problem. As purchased the bushings appear to be about .025 above the face of the gear.
2-As a solution would it be ok to take a small amount off the face of the transmission shaft so it will sit a little deeper in the flywheel and provide the clearance I need at the clutch hub?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Warren Mortensen, Ham Lake, MN on Saturday, July 09, 2011 - 11:51 am:

Face the triple gear bushings. This is standard procedure with the replacement bushings we have as far as I know. I did once get a set that were no improvement on the originals though. They should be made with a little extra meat on the shoulders so they can be brought into spec.

Don't know what you're situation is as far as machinists are concerned. I've always had one handy at my place of employment and have found you can get a lot of help by bringing 'em donuts or pizza, etc. "Government Work" makes the World go 'round.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush, Portland Oregon on Saturday, July 09, 2011 - 07:31 pm:

Did you install an old style bushing in the brake drum with the build in brass thrust washer? If not I would face the triple gear bushings and see where you are at.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Wilson on Saturday, July 09, 2011 - 07:44 pm:

Warren and Mark. Thanks for the input. I used the new style bushing in the brake drum so as suggested I will go ahead and face the triple gear bushings and if necessary just reduce the shims under the brake hub. I appreciate these and any other suggestions.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kenny Edmondson, Indy on Sunday, July 10, 2011 - 08:42 am:

Dave, The triple gears do need faced and try to have about .010 clearance when finished. Also make sure the bushing in the brake drum/high speed clutch is pressed in far enough before altering other parts or leaving out washers. Slide the main shaft (input) into the high speed clutch/brake drum and make sure it bottoms out against the flange.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Sunday, July 10, 2011 - 10:21 am:

Like Kenny said the front bushing in the brake drum has to be pressed in 1/4" beyond the end of the brake drum shaft or you will not be able to get the clutch drum washers to adjust.

Some time ago some one posted useing time saver yellow 320 grit on the bushings. At the time I thought it was not a bad idea, but now with a bunch of testing I think its a very good idea.

I will post later on what is found with tripple gear running clearance tests.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Wilson on Sunday, July 10, 2011 - 07:17 pm:

Thanks Kenny and Paul. I am having the triple gear bushings faced tomorrow. I checked the front bushing in the brake drum shaft and it is in as far as the old one and the main shaft is bottoming out ok. Going to do some further checking tonight. It seems to me that the gap between the brake drum and slow speed drum is too wide. I have used slow speed and reverse drums out of an older transmission and kept my original 27 brake drum. Maybe there is a problem with this. I will press of the driven gear again and take a look.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kenny Edmondson, Indy on Sunday, July 10, 2011 - 08:15 pm:

Dave, if your driven gear is fully seated, everything rotates and there's no excessive clearance then that assembly is ok. The only thing that can affect your assembly at that point is the bushing and triple gear face as mentioned earlier.


Top of pagePrevious messageNext messageBottom of page Link to this message  By James A. Golden on Monday, July 11, 2011 - 10:49 am:

The exact clearnace required between the triple gears and the flywheel has never been identified.

Is there a specific suggested value?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Hal Davis - Lyons, GA on Monday, July 11, 2011 - 12:16 pm:

I ran into the same thing. The triple gear bushings had too thick of a flange. I don't remember now where the interference was. It was either between the reverse drum and the triple gears or else just side load interference between the triple gears and drum gears. At any rate, the problem didn't show up until you install the clutch hub. My first thought was that the three washers had gotten hot and warped. I ordered new ones and it made no difference. I finally saw where the interference was and realized I HAD to face the triple gear bushings for it to work. Faced them off and have had no trouble since.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Wilson on Wednesday, July 13, 2011 - 12:05 pm:

Thanks to everyone for their help. As suggested, I faced the triple gear bushings to .010. Also, I forgot to mention originally that I had re-riveted the brake drum using slightly oversize rivets from Mac's. Upon close examination I discovered that the rivet heads were a little larger than the originals and therefor were sitting a little higher than the recess for the original rivets. I am in the process of grinding/filing the heads down and hopefully this, along with the facing of the bushings, will eliminate the problem


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Wilson on Wednesday, July 13, 2011 - 02:38 pm:

It worked! After facing the bushings and grinding the heads down on the oversize rivets, everything went together as it should. Thanks again to all for your help.


Posting is currently disabled in this topic. Contact your discussion moderator for more information.
Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration