1940 merc rear end?
 

What does a 1940 mercury rear measure from drum face across to the other...?..60" guessing.

Re: 1940 merc rear end?
 

I know you didn't ask but a 40 Ford distance is 59 1/2 in WMS to WMS.

Re: 1940 merc rear end?
 

Are 1940 fords the same?

Re: 1940 merc rear end?
 

I don't know if 40 Fords and 40 Mercs are the same.

Re: 1940 merc rear end?
 

For one thing, I'm remembering that the drive shafts/pinions are of a one piece design on the Mercs. Doing a little research on the H.A.M.B., the '39-'41 Mercs AND 1941 6-cylinder Fords had this goofy 1-piece drive shaft/pinion gear. I never understood the reason for that. That fact alone would make me question whether they're the same width. Wonder if Kubarth might have a clue?


Maybe someone can look at one of the parts books/Green Book. IF the axles and bell housings are different lengths on the Mercs, their part number would likely begin with a "99A-" prefix. Otherwise, they should match the '37-'41 Ford prefix of "78A-" for bells and "81A-" for axles.


The '39-'41 Mercs had a 116" wheelbase whereas the '39-'40 Fords wheelbase was 112". I'd bet that Merc torque tube measures close to 74". The '39-'40 Ford t-tube is 70".


So banditomerc …..If you're possibly thinking about substituting a Ford rear for a Merc rear, it won't work....EASILY! Even if the widths are the same, that goofy pinion/driveshaft is longer than the Ford counterpart. Using a Ford rear, the t-tube/drive shaft combo will be too short. And there will be no EASY way to lengthen the torque tube and driveshaft/pinion to match the Merc length. DD

Re: 1940 merc rear end?
 

I believe the Merc's is one piece pinion/driveshaft and longer...............
Paul in CT

Re: 1940 merc rear end?
 

If i can't find the right rearend ill just swap out for something else

Re: 1940 merc rear end?
 

banditomerc…...What exactly is wrong with your rear end? Depending on what the problem is, we MAY be able to come-up with a parts solution. DD

Re: 1940 merc rear end?
 

I do have a 40 Merc rear end.

Re: 1940 merc rear end?
 

Merc & Ford are externally dimensionally the same. Yes, to the above comments about different driveshaft/pinion. And, the difference in WB has nothing to do with the rear end. The 4 inch difference in WB is entirely forward of the firewall.
To the original question, post #2 covers it.
To post #9, please measure D-2-D to confirm for post 1 & 2. Thanks

Re: 1940 merc rear end?
 

The frame was even damn near the same but longer forward of the firewall. They even had that weird wishbone ball adapter to move it forward to the new wheel base. I think they just wanted it a bit heavier duty for the new Mercury 239 CID engine so they did away with the spline coupler and made the shaft solid. A few years later they changed back to the normal Ford design with the coupler but the war put a stop to production in early 1942 .

Re: 1940 merc rear end?
 

That '40 Merc rear you have must at least have a drive SHAFT still attached, right? IF it still has TORQUE TUBE attached, could you possibly measure the TOTAL length of the T-tube from the front end bell, back to and including the 6-bolt banjo flange? ONLY if the torque tube is missing, could you possibly measure the length of the drive shaft from FRONT splined end to the flat, 6-bolt surface on the front of banjo? Surely would answer some questions here! Thank you....DD

Re: 1940 merc rear end?
 

Hopefully I can check it tomorrow. There is no torque tube.

Re: 1940 merc rear end?
 

Thanks, Jack....should be interesting! ANYONE else have a KNOWN '39-'41 Merc torque tube that they wouldn't mind measuring precisely? DD

Re: 1940 merc rear end?
 

The length should be the same as Ford but the radius rods might be the shorter type that were used later on Fords. The part numbers are all 99A for the torque tube and the radius rods. The 99A radius rods were also used on the 1941 Ford passenger cars. In 1942, the number of the radius rods was changed but they look pretty much the same to me. I have a 41 car rear axle and it has the short radius rods.

Ford used the long radius rods for passenger cars through 1940 and for the Commercial pickup in 1941.

Re: 1940 merc rear end?
 

I didn't see this posted so I looked in my 40 Ford and Mercury Chassis book and it lists the same axle part number for both 112 and 116 meaning Ford and Merc so the width must be the same.

Re: 1940 merc rear end?
 

Thx guys...got one.
..

Re: 1940 merc rear end?
 

A 40 Merc driveshaft measures about 73 5/8" from the end of the shaft to the face of the flange on the dif housing.

Re: 1940 merc rear end?
 

The torque tube shouldn't be much different than that figure. I thing the 42 & later Ford cars TQ tubes were 71 7/8". If that's the case then the Mercury would be longer. It would be interesting to know the actual figure though.

I believe the 112 inch wheel base Ford car torque tubes for the 38 thru 40 cars were 69 15/16". The 35 thru 37 cars should be close to that too since they had the same basic frame design. Only the motor mounts were different for the 35 & 36 cars before the block mounted pumps came out in 37. The dimensions from the engine to the rear axle should be pretty close.

Re: 1940 merc rear end?
 

I've got to agree, which means we are now in the neighborhood of 4" LONGER than a 1940 torque tube which is 70" long. That's also about 2-ish inches longer than a '41-'48 FORD t-tube which is 71-3/4" long. I have read a couple of descriptions of these elusive Mercury t-tubes on the H.A.M.B. stating that the Mercury tubes (at least the '39-'41 Merc tubes) have some sort of a 4"-ish SPACER welded into the tubes to lengthen them to the dimension necessary. This "old Ford" mechanical and suspension stuff has always intrigued me, especially when Ford Engineering utilized SOME parts swapping and overlap usage to develop new, or updated assemblies for subsequent models. The oddball 1941 Ford suspension differences is a good example of this. Now, this Mercury torque tube/drive shaft has come back to light and I'd really like to find-out ALL the particulars on these two obviously-misunderstood parts and their reason for being different. I still feel like the extended wheelbases (although all lengthening supposedly took place in front of firewall) play SOME part in the lengthening of these torque tubes/d-shafts. So PLEASE, STILL searching for someone with a KNOWN-TO-BE '39-'41 MERCURY torque tube for some measurements and details! DD