How To: C15a Wire-3 restoration

[Phil Waterman]

Hi Jordan

I bought a NOS transmission a couple of years ago and it had been sprayed or dipped in cosmoline which had dried out. Took same sort of treatment soaking with degreaser then washing down with 160F hot water to get it clean.

You nailed the problem of cleaning hot water works much better than cold or even room temp.

How do all the bearing look? Was there any sign of water having been in the case, ie any pitting on the gears?

Enjoy your restoration reports.

Cheers Phil

PS I've painted the last couple of transmissions after assembly but before adding gear oil with Por15 black. Seems to help seal the gasket edges from leaking.

[Jordan Baker]

Thanks Phil

There was some very minor rusting on two of the gear right at the bottom of their rotation. When I drained the oil about two teaspoons of water came out first. I’ve ordered new bearings via eBay yesterday. Will hopefully have them next week. The bushings in the reverse gear are still in great shape with no side to side play on the shaft. I’ve cleaned up the gears using a brass wire wheel on an electric motor. That removed all of the rust scale. There is no pitting and very minimal wear on the gears. The cast bearing retainer housings were also polished up on the brass wire wheel. I’ve got all of the bolts and washers being cleaned up in my media tumbler. All in all this has gone smoothly.

For my colour I decided on using Ford Grey. I know I know but the online Chevy folks say it’s a good representation of the Chevy grey. I also figured the lighter colour would be easier to spot any leaking.

[Jordan Baker]

The cast parts and gears all polished up.

[Bob Carriere]

...."I’ve ordered new bearings via eBay yesterday". ......

these are the two lower one I assume...... were they visibly pitted..? curious about the rear bottom one which was problematic to match a few years ago. Could you share how it fits and possibly the source.

On the gears....... I took a fine diamond stone and went over the leading point of the teeth one by one to reduce the wear pattern evenly .....cause by crash shifting in its previous life.....sometimes only a few needed some minor dressing....hoping it would help my shifting in the future.

Have you decided on the oil you will use???? I have used synthetic from Lucas and as predicted it tends to leak ever so lightly...... a particular feature of synthetics is the ability to creep into tiny crevices/space. .....but then it is a CMP and they love marking there territory.

Bob C

[Jordan Baker]

I just went by the part numbers and the cross reference numbers Rob Love had dug up. I ended up getting all 5 bearings on eBay. As for the originals. Yes the bottoms ones had rusting and some rust flakes inside them. The upper ones look ok but I figured with it all apart I may as well replace them too.

I haven’t looked that far ahead yet for what oil I’ll use. My Willys MB seems to like the 80/90 transmission hypoid oils.

I compared my gears to some NOS ones on eBay and found mine were looking pretty much the same.

[chris vickery]

If in doubt bead blast the gears which will reduce stress in the steel

[Bob Carriere]

It's the bottom rear bearing.......keep me posted of what that bearing looks like and how well it fits.

Thanks

Bob C

[rob love]

Originally Posted by Jordan Baker

I haven’t looked that far ahead yet for what oil I’ll use. My Willys MB seems to like the 80/90 transmission hypoid oils.

Not all hypoid oils are the same. The most current spec of hypoid is GL4 edited to add: now GL5) which is reported as harmful to brass. Not a problem for your Chevy crash box, but any transmission with synchro rings may not have a happy ending.

What belongs in those is GL1 or possibly GL3 specification. Tough to find...ask any Dodge Diesel owner with a manual transmission. I ended up using royal purple.....expensive, but cheaper than removing and repairing the transmission.

Bob: I always considered the oil leaks on a chevy quite standard. Many of them here at the museum feature multiple drain pans underneath them.

[Robert Bergeron]

Rob/ Jordan : Gl4 could explain the early demise of the 2 nd gear and it’s brass syncro ring in my GPW transmission a couple of years ago ...