What happens in a transmission rebuild - Part 8

[Mac VP]

LINK TO ORIGINAL POST:
https://www.fordbarn.com/forum/showthread.php?t=278347

This will be a brief section dealing with the main drive gear and the cluster gear for this transmission. Naturally, both parts have already been cleaned and inspected.

The front ball bearing must be pressed onto the journal of the main drive gear. The front oil baffle is dropped in place first. These are slightly offset to allow a bit of space for the 16 teeth of the drive gear to reside. The bearing has a snap ring groove offset to one side......this will always go toward the front.

The fit of the bearing to the drive gear is a tight press fit. Our press is rated at 20 tons and can handle this with ease. Always put a couple drops of oil on the journal surface before pressing something into place. We use an old bearing race to support the inner race of the new bearing while pushing on the front pilot end of the drive gear. Make sure that the oil baffle is not sitting slightly in the snap ring groove before you began to apply pressure. Once past the groove, you don't have to worry about the baffle as it will travel with the new bearing into place. Make sure that the bearing is fully seated, and that the snap ring groove in the drive gear is just beyond the edge of the bearing.

The B-7064 snap ring can now be installed with your lock ring pliers. Make sure that it is fully seated into its groove. Then install the large snap ring (B-7026) in the outer groove of the new bearing.

The complete main drive gear & bearing assembly can be installed to the front of the gearbox case. The fit is usually pretty close so you may have to tap the front of the input shaft with a soft hammer to seat the bearing to the case. Use a single bolt and washer to secure the assembly to the gearbox for now.

[Mac VP]

The second part of this post covers the cluster gear. As you can see from the photos, this type uses the caged roller bearings with the spacer tube in-between. The LONG (B-7121) always goes to the rear, which is the small end of the cluster gear.

We lubricate the bearings with a light oil, and we use some of the green colored assembly grease inside the cluster gear bore. The bearings and spacer tube are assembled. Then we apply a bit more grease to the back end of the cluster gear and place the rear thrust washer in place. The washer shown here is the single type with the 4 prongs on one side......these fit into the 4 grooves machined into the back face of the cluster gear.

[JSeery]

Really interesting series Mac! Thanks for the effort.

[28fordroadster]

Is it a problem if the input shaft bearing slides onto the shaft without needing to press it on? Mine went on very easily.
Thanks for thr great info
I am currently installing an LZ gear set into an open drive trans

[Mac VP]

That’s not a good thing….the inner race of the bearing can spin on the bearing journal of the main drive gear. Hard to say why your gear journal is too small. You could try fitting another bearing on the gear just to double check the fit. Normally, the front ball bearing must be installed with a hydraulic press. I am not a fan of heating up a new bearing to expand it for the installation. You will probably have to replace the main drive gear.

[glennpm]

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This is great Mac. Thanks for taking the time to present it so well and especially sharing it with us.

Glenn

[28fordroadster]

It’s an LZ input shaft that looks to be in excellent shape. It’s installed and I’m seeing some wiggle. I guess I should take it back apart and compare it to others that I have here. Is there a standard size of the input shaft surface that the bearing rests on?

[rotorwrench]

The looser it is the quicker it gets more looseness. It likely already has a spin issue. A person might be able to have it knurled and then use loctite but it depends on what the current clearance is. Normally it's an interference fit. New Lincoln gears should be available.

Don't hesitate to start a new thread. Mac's series of posts are a tutorial on the subject.

[Mac VP]

For those who would like to get to the beginning of the rebuild thread, go to the first page of the rebuild project:

https://www.fordbarn.com/forum/showthread.php?t=278347

[Tim Ayers]

Thanks for posting this Mac. Great work.