Rear End Temperature

[carolinamudwalker]

How hot should the rear end get after an hour's run. outside temp about 90 deg. Mine gets too hot to hold your hand on. The torqe tube also is hot but not as bad. I have had it apart during a TX swap out and replaced the bearings and cups (races) in the rear end. Maybe I am just being paranoid. BTW Model A only TX kit is super, Thanks Bob

[Mitch//pa]

there is no spec of how hot a differential will get .. on a 90 deg day after a good run yea you wont be able to hold your hand on it.. if your preloads are to tight you will know soon enough as your bearings will be torn up and noises will occur. from my experience this wont take to long to happen...a modeL A rear gets very little preload almost to the point where just the end play is removed

[Tom Wesenberg]

A few years ago I drove my 28 Phaeton 17 miles when the air was in the upper 80's. As soon as I got to my friend's house I shot the differential temp and it was only 95*. This is a good unrestored rear end.

[Tom Endy]

If the banjo became so hot you couldn't put your hand on it after a rebuild, my suspicion is the pre-loads on the carrier bearings and the pinion bearings were not set properly. In the case of the carrier bearings if they are too tight they can cause the bearing mount to spin on the carrier hubs instead of the roller elements rolling in the races. This is metal turning on metal and will certainly generate heat. In the case of the pinion bearings set too tight I have seen cases where the double race in the banjo spun. This will also generate heat.

Many on this forum have seen and used the differential rebuild dissertation posted on the web site of the Santa Anita A's of Arcadia, California. www.santaanitaas.org Recently I did a rebuild for a club member and during the process I did a photo shoot of the entire process, which included having to remove the new carrier bearings to install shims. The photo shoot includes 65 photos with text.

This document has recently been posted on the web site right below the differential dissertation. Go to the home page of the web site and put your cursor on "Technical Reference", my name will appear below, click on it and it will bring up a menu of articles.

Scroll to "differential". The two articles are the differential rebuild, revised 2014, and right below, the photo shoot, 2015.

All are welcome to download and print these articles out.

Tom Endy

[H. L. Chauvin]

Rear End Temperatures

Something about the month of April ....... mine always increases before the 15th ..... and then cools off gradually after the 15th.

Nothing like a most sincere different Model A opinion now and then.

[BILL WILLIAMSON]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by H. L. Chauvin

Rear End Temperatures

Something about the month of April ....... mine always increases before the 15th ..... and then cools off gradually after the 15th.

Nothing like a most sincere different Model A opinion now and then.

Well, H.L, I file mine REAL EARLY & send a SAD note with it I "guess" I sound SO PATHETIC, they send me a CHECK Try it!
Bill W.

[silversink]

98.6

[H. L. Chauvin]

Hi Bill,

I started to send a note with my tax form also, to Lois Lerner that is, that she qualified for nomination in the "McGuiness World Records" because she was the first female in all of history who went before a large group was asked to "talk".

Instead of running her mouth like a Poll Parrot .......... she surprised and shocked the entire World and did not utter a single word.

On second thought, it could get dangerous if one intentionally raised her Rear End Temperature.

-------------------------------------------------------------------------------------------
On a Serious Note of Appreciation:

In his reply No. 4 above:

Mr. Tom Endy should be highly commended for sharing his knowledge and taking his most valuable time to write such wonderful, detailed articles on disassembly, rebuilding, and reassembling Model A differentials; and also for continuing to add additional revised notes from time to time to his first original writings.

[SAJ]

I read on Fordbarn or somewhere else and wrote down that rear diff permitted temp is ambient plus 90 to 110 deg F. I re-used old bearings on the pinion in my wifes Tudor, set at 15 lb-inch preload. It ran at 113 deg F round town on a 77 deg day and 150 after a run at 55mph down the motorway. I felt this was OK considering the double cone was removed from another car and polished up due to that car's diff having partly destroyed itself and put metal particles throughout the casing. The Tudor's diff now runs cooler and is very silent after 1200 miles of running.
I used the old bearings because I could not get a new double cone in NZ at the time. I always favour new parts if possible but I got away with it this time.
Hope this information helps.
SAJ in NZ

[carolinamudwalker]

Thanks everybody, I really dont want to tear it down again. Will monitor temp with infra red gun for a while and see what happens. Might be sorry Bob

[Dick So. Cal.]

I have checked the differential temp and tranny temp several times and they both run about 134 deg after an extended run. While I was at it, I checked the brake drum temps to see if I had one out of adjustment. The temp varies but I look for temps that are the same (within a reasonable number . . 10-15 deg?) on all four drums.

All this is just a sanity check for me.

Dick

[Mitch//pa]

Originally Posted by Dick So. Cal.

I have checked the differential temp and tranny temp several times and they both run about 134 deg after an extended run. While I was at it, I checked the brake drum temps to see if I had one out of adjustment. The temp varies but I look for temps that are the same (within a reasonable number . . 10-15 deg?) on all four drums.

All this is just a sanity check for me.

Dick

thats more like it and they get hotter than that on a hot day and a good run.. your not laying your hand on it

[Fullraceflathead]

Using a Infrared Gun to check temps is best.
The Hand will feel like it's burning (Too Hot) at around 110-120 degrees.