3:27 Gear

B

BrianTanner

Junior Member
Hey guys,
I just bought a 3:27 replacement gear for the rear end differential for my 31 tudor sedan to get her cruisin on the highway a bit easier. I have never worked on a rear end and really just want to know how difficult this job would be if I did it myself. I am not a mechanic, but I am pretty good with cars. Is it a pretty straight forward process or do you recommend taking the car somewhere and having it done professionally? I would like to do it myself, but dont want to cause myself a giant headache and accidentally cause problems for myself.
Thanks as always,
Brian
 
BrianTanner said:
Hey guys,
I just bought a 3:27 replacement gear for the rear end differential for my 31 tudor sedan to get her cruisin on the highway a bit easier. I have never worked on a rear end and really just want to know how difficult this job would be if I did it myself. I am not a mechanic, but I am pretty good with cars. Is it a pretty straight forward process or do you recommend taking the car somewhere and having it done professionally? I would like to do it myself, but dont want to cause myself a giant headache and accidentally cause problems for myself.
Thanks as always,
Brian
Click to expand...

Well, IMO that is a fairly expensive piece of merchandise to take a chance on getting the set-up correct. Too much lash will likely take the tip of a tooth off, and too little lash will likely cause overheating. Both can causes noises that once the wear pattern is established, it will be there forever. I am not sure any of us can make that decision for you. It is you that said you are not a mechanic yet you are good with cars. That seems contradictory to me.

Therefore we can all encourage you to try if that is what you want to do but would the people still encourage you to do it yourself if they each had to personally pay for any damages due to your mistakes? Probably not. Therefore be cautious of the advice you receive, ...including mine!! ;)

.
 
In my opinion you should have a good manual such as The Model A Mechanic's Handbook and read and understand the procedure for installing a ring gear and pinion and then decide if you want to tackle it. Do you know anyone who has done the job that would assist you? Do you have the tools? Such as hub puller, spring spreader, bearing seperator, axle seal installer?
 
I like to learn to do the jobs that I will be doing in the future (plugs, points, condenser, brakes, etc). If you have the rear end done properly you should never have to touch it again in your lifetime (and probably the lifetime of your children). I vote to farm it out to someone that knows what they are doing. Be sure to read Tom Endy's write up on redoing the rear end before your decide (OCMAFC.com, then Tech Articles, then Tom Endy's Tech Articles and finally Differential Seminar).

Charlie Stephens
 
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About 10 years ago I helped my friend install a 3.27 ring and pinion. It was very slightly used, which was no problem, however we had a problem with the pinion taper being very slightly off fron the driveshaft taper. We had to take it to a machine shop and have the driveshaft taper trimmed to match the pinion gear. After that it went together fine. I've never heard this problem reported by anyone else, so it might have been a mistake on the pinion gear for only this one. At least we can hope so. :) Some day I'd like to go with the 3.27 also.
 
I have done it, but it's a big job removing the rear end and so forth. Get help. I installed a 3:54 but wish I had used a 3:27.
 
A 3.54 is not a very "high speed" ratio. You'll get only about a 5% speed advantage at a given rpm. 2 mph at 40, 2 1/2 mph at 50. If you're a flat lander, a 3.27 would do a good job.
 
the worst part about the rear axle rebuild is the mess for me
i know that the shop will stink like gear oil for a week and its going to take a few hours just to clean everything up to inspect it.
if you do it yourself, don't be surprised to see A LOT of stuff it bad or borderline bad and you'll have to do some parts hunting.
tk
 
BrianTanner said:
Hey guys,
I just bought a 3:27 replacement gear for the rear end differential for my 31 tudor sedan to get her cruisin on the highway a bit easier. I have never worked on a rear end and really just want to know how difficult this job would be if I did it myself. I am not a mechanic, but I am pretty good with cars. Is it a pretty straight forward process or do you recommend taking the car somewhere and having it done professionally? I would like to do it myself, but dont want to cause myself a giant headache and accidentally cause problems for myself.
Thanks as always,
Brian
Click to expand...
Brent gives real good advise on this . 2001 I had 3:27 installed in my 31 Tudor, in 2003 installed Mitchell 26.7% overdrive getting ready for the GREAT RACE. I would not change this set up for anything, it's great. I did not do it all myself to scared to mess things up. I say hire the job out for your gear work it's to much of a gamble to screw up. All the na sayers will tell you you wont like the 3:27 because its to high, this is what i heard back in 2001 but I knew how my car ran. MR Mitchell with his great over drive wasn't sure it would work , at the time he didn't know of any one running this with his unit. WORKS GREAT . Only recently people are starting to see the good side. have fun modelAtony tony white Lafayette,LA
 
I would do it myself if I were you. There is no hurry, so you can take your time and use care with every step. It would be nice to have someone near that can advise you if needed. Tom Endy is very experienced, so follow his article on it. Also Les Andrew's book is a great one to have on hand. One thing I don't recommend is to bolt it all together with no gaskets as recommended by Les as this can distort the housings and cause leaks. Be careful when removing the rear spring, everything else should be relatively easy.
 
My Dad and I just did one. Had to take a few thou off the pinion sleeve but all pretty straightforward if you take your time and follow Tom Endy's advice.

Ran it in with a 700 mile round trip to the Pendine Speed Trials last weekend.

Sat at a relaxed 55mph cruise on the way there and 69.87 on the sand.

Very pleased with it
 

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Brian,

I See your in St. Louis. I am the mechanical guy in the Model A Club in the St. Louis area. My specialty is chassis rebuilding/rear ends/front ends.. etc. I have done many. I will help you if you wish... I can help in the disassembly and inspection and you can do the cleanup for the rebuild with Re-assembly and restoration to follow. Rear brake rebuild if required would may be in order then as well. I am always busy but will assist if you like.

I will drop you a PM.
Larry Shepard
 
larrys40 said:
Brian,

I See your in St. Louis. I am the mechanical guy in the Model A Club in the St. Louis area. My specialty is chassis rebuilding/rear ends/front ends.. etc. I have done many. I will help you if you wish... I can help in the disassembly and inspection and you can do the cleanup for the rebuild with Re-assembly and restoration to follow. Rear brake rebuild if required would may be in order then as well. I am always busy but will assist if you like.

I will drop you a PM.
Larry Shepard
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Now that is a bargain!
 
That's what I really like about the Model A hobby. If someone needs help, others nearby will step up.

Even though Brian will not do this specific job very often, this is a good way to learn how to do it "for the future".
 
I am no mechanic, just a back yard one. and I had never been inside a early Ford rear in till now. I had to replace the axles in my A. also I changed from 4.11 to 3.78. I did it and it works. you just need to read up and take your time, and don't be cheep like me. i used the original carrier because the bearings where good. i should have put new barings on the carrier that the axles came from. witch i did it cost me about 15 hrs of time for being cheep!
 
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