Differential case collar repair

Discuss all things Model T related.
Forum rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules
User avatar

Topic author
ArthurB
Posts: 59
Joined: Wed Jan 09, 2019 5:22 pm
First Name: Arthur
Last Name: Babitz
Location: Hood River, Oregon
Board Member Since: 2018

Differential case collar repair

Post by ArthurB » Thu Feb 06, 2020 7:59 pm

I went to start reassembling my axle for a test fit and realize I failed to measure one thing: the outer collar on the left half differential shell, which keeps the steel washer and thrust washer centered, is badly worn. It's cone shaped where the old babbitt washer was, at least 1/16 if not 1/8 under. It's fine where the steel washer is. I imagine it's not OK to have my nice new bronze washer slipping around without a good center, so my question: I have a good local machine shop. Does it seem reasonable to have them machine away part of the collar and slip an nice steel collar over it? I haven't seen a lot of nice differential cases offered for sale so I'm tempted to try to salvage this one, unless there's a good reason not to. I do have a "spare" differential case but it has several serious flaws that caused me to put it aside when I started this project. My replacement was OK in all the places the old one wasn't, but I failed to check this collar.

User avatar

Pep C Strebeck
Posts: 146
Joined: Sun Jan 06, 2019 11:12 am
First Name: Joseph
Last Name: M
Location: MI
MTFCA Number: 0

Re: Differential case collar repair

Post by Pep C Strebeck » Thu Feb 06, 2020 8:29 pm

I had a similar issue and I bought a repaired/rebuilt differential case half from Bob Bergstadt, all repaired and ready to go. Everything fit right back to factory specs. He lists them here on the forum from time to time and on Ebay or you can call him at Bob's Antique Auto Parts bobsantiqueautoparts.com
"Remember son, there are two ways to do this: The right way, and your way” Thanks Dad, I love you too.

LOOKING FOR A LUFKIN Model 1671A Center Punch.


FATMAN
Posts: 620
Joined: Sat Jan 19, 2019 9:28 am
First Name: ROBERT
Last Name: BERGSTADT
Location: LOVES PARK IL
MTFCA Number: 1575

Re: Differential case collar repair

Post by FATMAN » Thu Feb 06, 2020 9:29 pm

I have them in stock --815-633-7244
Bob


FATMAN
Posts: 620
Joined: Sat Jan 19, 2019 9:28 am
First Name: ROBERT
Last Name: BERGSTADT
Location: LOVES PARK IL
MTFCA Number: 1575

Re: Differential case collar repair

Post by FATMAN » Fri Feb 07, 2020 1:07 pm


User avatar

Topic author
ArthurB
Posts: 59
Joined: Wed Jan 09, 2019 5:22 pm
First Name: Arthur
Last Name: Babitz
Location: Hood River, Oregon
Board Member Since: 2018

Re: Differential case collar repair

Post by ArthurB » Sat Mar 14, 2020 9:06 pm

Quick follow up to finish this story, in case it is useful to others:

I found that McMaster Carr will make a custom bushing from Rockwell C61 steel for $43. You give them ID and OD, as well as height, and they make to the nearest 0.001". The only catch is you have to wait 3 weeks. While Bob had a nice differential case in stock there was the challenge of repairing instead of replacing.

I turned the old differential on a lathe to make a uniform collar, measured it with dial calipers and used that for ID, with the Ford spec OD and height. As you see the old collar is a little short too, but that leaves me some room for a couple of welds to tack it in place. It pressed on pretty tight, but I'm not sure what sort of forces and vibrations are present at the differential so I will tack it in place. Can't wait to finish this assembly. It's been spread all over my garage for a month.
IMG_4766 copy.jpg


Adam
Posts: 527
Joined: Sun Jan 06, 2019 11:57 am
First Name: Adam
Last Name: Doleshal
Location: Wisconsin
MTFCA Number: 23809
MTFCI Number: 1
Board Member Since: 2000

Re: Differential case collar repair

Post by Adam » Sat Mar 14, 2020 9:13 pm

The differential part is cast. Not sure if its gray iron or ductile iron. You might make a mess if you try welding on it. If its gray iron it will be like welding on a rock. If its ductile, results may be slightly better.


d stroud
Posts: 729
Joined: Sun Jan 06, 2019 10:45 am
First Name: David
Last Name: Stroud
Location: Mound City, MO. 64470
Board Member Since: 2011

Re: Differential case collar repair

Post by d stroud » Sun Mar 15, 2020 3:30 am

Adam, there are (or at least were ten years ago) several arc welding rod suppliers that make several rod types for welding on various cast irons and welding cast iron to steel. They can be a bit spendy, but work great using the proper techniques. Some leave a machinable deposit, some don't. I have repaired many castings by welding to a piece of steel. Most all suppliers have handbooks with all of the recommendations and procedures. Dave
1925 mostly original coupe.


Adam
Posts: 527
Joined: Sun Jan 06, 2019 11:57 am
First Name: Adam
Last Name: Doleshal
Location: Wisconsin
MTFCA Number: 23809
MTFCI Number: 1
Board Member Since: 2000

Re: Differential case collar repair

Post by Adam » Sun Mar 15, 2020 11:33 am

D Stroud, You are correct. HOWEVER, the vast majority of hobbyists as well as some professionals are unlikely to have the right equipment, supplies, or skills. A well equipped, experienced welder can weld just about anything given the right circumstances. Some people can make a mould and cast and machine these parts themselves too...

User avatar

Topic author
ArthurB
Posts: 59
Joined: Wed Jan 09, 2019 5:22 pm
First Name: Arthur
Last Name: Babitz
Location: Hood River, Oregon
Board Member Since: 2018

Re: Differential case collar repair

Post by ArthurB » Sun Mar 15, 2020 7:58 pm

Thanks for the warning, Adam. I have access to a skilled welder-- I'll pass along your warning. I have a spare wrecked casting to practice on if he has the right equipment.

I probably should trust the press fit anyway, but this is a learning process so I'll see what I can learn about welding to castings.


Adam
Posts: 527
Joined: Sun Jan 06, 2019 11:57 am
First Name: Adam
Last Name: Doleshal
Location: Wisconsin
MTFCA Number: 23809
MTFCI Number: 1
Board Member Since: 2000

Re: Differential case collar repair

Post by Adam » Sun Mar 15, 2020 9:41 pm

Arthur B, You have it perfectly figured out. Having your welder practice on a junk casting is an excellent way to proceed.


rgould1910
Posts: 197
Joined: Tue Jan 22, 2019 8:16 am
First Name: Richard
Last Name: Gould
Location: Folsom, CA

Re: Differential case collar repair

Post by rgould1910 » Mon Mar 16, 2020 12:02 pm

Why not use Loctite sleeve retainer?


Scott_Conger
Posts: 2221
Joined: Sun Jan 06, 2019 11:18 am
First Name: Scott
Last Name: Conger
Location: Clark, WY
Board Member Since: 2005

Re: Differential case collar repair

Post by Scott_Conger » Mon Mar 16, 2020 6:37 pm

Richard

I was wondering the same thing, but too late now.
Scott Conger

Full Flow Float Valves - deliver fuel like Henry intended!

Post Reply Previous topicNext topic