What happens in a transmission rebuild - Part 6
 

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

This part is going to cover the preparation of the gearbox case (7006 in the drawings). The 1949-50 Mercury transmission case was very similar to the earlier types (32-39 toploaders and 40-48 sideloaders) in that they have the large round bell shape at the interface to the engine. The casting also carries the clutch release shaft, with the release bearing and hub.

Now that the casting has been cleaned and painted, we do a quick check and clean of all the bolt hole threads. We use old worn out taps to run through each bolt hole. This provides a final cleaning to remove any small particles of dirt or rust that survived the oven bake process. We want these threads to be clean for the eventual sealing thread locking compound that will be used on the retainer bolts.

This type gearbox case will have two bushings to support the clutch release shaft that passes through the gearbox. Most of the early Ford transmission cases used the thin wall bushings (approximately .030" wall thickness). As Ford moved through the 1940's they started to bore out the cases for a thicker bushing (about .060" wall thickness). All of the 49-50 Mercury cases use the thicker bushing. These do not come predrilled for the grease zerk fitting passage, so we have to score the center and drill them for this opening. The steel shell of the bushing is rolled so there is a very fine seam...drill the hole opposite the seam. I used a 1/4" bit but you can use up to 3/8" diameter. Clean off the chips and remove any burrs before installing.

Lubricate the bores to accept the new bushings. Place the bushing at the opening, lining up the grease hole with the zerk fitting hole in the case. We use a simple bushing driver to tap the bushings into place. They are typically pretty tight when installed.

The overdrive adapter casting will have the solenoid oil seal installed. This fits into the small recess of the face that holds the solenoid itself. A bit of sealant is used here to help keep the seal in place.

Re: What happens in a transmission rebuild - Part 6
 

Thank you Mac,
I never really paid attention to how similar the later cases were to the pre 49 ones. How much, if any, internals are the same, or interchangeable?
I turned down some free later OD transmissions awhile back because I thought I would have no use for them. :(

Re: What happens in a transmission rebuild - Part 6
 

The Mercury units from 1949 thru 1950 and some in early 1951 model year were the close ones to the early Ford type gears. The overdrive is what made most of the differences.

It's coming right along.

Re: What happens in a transmission rebuild - Part 6
 

Gentlemen. I am removing my comment. It was not appropriate. Apologies to members and especially the OP for messing up his thread.

Re: What happens in a transmission rebuild - Part 6
 

Me TOO...sorry! DD

Re: What happens in a transmission rebuild - Part 6
 

This also was not helpful.

Re: What happens in a transmission rebuild - Part 6
 

There's never been any doubt that Mac's hands are gifted with the best of them. DD