Q: 34 Diff: torque on housing/ pinion preload etc.

[fordson]

Huh, reassembling the differential of my 34 coupe.
Cant find the exact torque specifications on the housing/diff/pinion bolts and nuts. Can anyone please help?
Thanks

[Mart]

Housing I'd shoot for 35lbs. Don't try it unless genuine Ford bolts. Same for the torque tube to the diff housing. The pinion is a tricky one, the two nuts need to be wrung together very tightly, while not overloading the pinion bearings. There are threads here describing a method to check for pinion tightness by holding the pinion in a vise and spinning the housing. 1-1/14 turns is about right.

[fordson]

Hey Mart,
thank you so much for your reply. My car beeing in South Africa, makes it difficult since there are no people with that kind of knowledge or advice available. I was hoping for some figures out of literature or ford manuals. Ill try to find the thread on pinion tightness, but your advice is much appreciated. Great to hear from England, you guys have a great traditional scene. Will visit the Hay Ride one day and look out for you👍
Many regards Randolf

[fordson]

Any other cracks out there that can help?

[JSeery]

Do you understand how to set up the rear axle? If not there is some step by step information. The one I am familiar with is model A, but they are all similar.

[Terry,OH]

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For 34 the Spec. for the pinion nut adjustment is 12 to 17 inch/pounds of torque to turn the pinion. Ring pinion tooth back lash is .006-.010" There is no torque Spec. for the bolts that connect the torque tube to the differential center housing or the axle housings to the center housing, or the ring gear attachment. Mfg. Spec. for a soft grade 5 bolt 3/8-24 new is 21 foot/pounds (without lubricant). I would not torque old Ford bolts to that Spec.

[Lawrie]

Does not the inch pounds vary if you use new or used bearings.
Lawrie

[JSeery]

Lawrie is correct I believe.

[Terry,OH]

No the Ford Spec. does not vary with new or used bearing and races. Could consider the bottom end of the Spec. or the top end. If you don't want to use the Ford Spec. that is up to the installer.

[Bored&Stroked]

Well - pretty much everybody I've listened too gives quite a different spec for used versus new bearings . . . like a factor of 1/3 to 1/4 the figure used for new bearings. Not claiming to be an expert, but I've definitely seen this as a pretty consistent opinion.

[Lawrie]

look in the service bulletins , there IS a difference for new and used pinion bearing preload.
Lawrie

[Terry,OH]

See posting #9 above.

[ford38v8]

Originally Posted by Mart

...There are threads here describing a method to check for pinion tightness by holding the pinion in a vise and spinning the housing. 1-1/14 turns is about right.

Mart is correct. This method may actually be the most accurate. Mount the pinion shaft in a bench vise, with the banjo up. Spin the banjo hard and fast as you can. When adjusted correctly, the banjo will make one full turn only. Lock the nuts together and test it again to achieve the same results. You'll find that all the old timers used this method with consistent positive results.

[fordson]

Originally Posted by JSeery

Do you understand how to set up the rear axle? If not there is some step by step information. The one I am familiar with is model A, but they are all similar.

JSeery, iam not familiar with the set up of a rear axle !
Where will i find the step by step information, is there a thread or link available?
Thank you

[fordson]

Ok, that is a lot of excellent information and i thank everybody for their input. I use new bearings so will orientate myself along Terrys figures.
Thank you very much.

[fordson]

Originally Posted by Lawrie

look in the service bulletins , there IS a difference for new and used pinion bearing preload.
Lawrie

Lawrie: i wished i had those service bulletins. Is there no such thing as a Internet- Library on Fords Service Bulletin, one can read up on and do research?
Are they available as reprints?
Thank you!

[JSeery]

Not sure where I saved it, I'm looking! Here is the VanPelt page: http://www.vanpeltsales.com/FH_web/f...le_service.htm

HAMB link: https://www.jalopyjournal.com/forum/...o-axle.812569/

[Bored&Stroked]

I'm working on building a couple late 32 - 34 rears as I write and also a Winters V8 style banjo (which uses a very similar dual tapered bearing pinion setup). Winters also makes a V8 style quick change - very similar to a Halibrand V8 QC. Anyway, their Street Rod technical manual - available on their website - has some great setup information and much of it applies to our rear ends (which is where all the original V8 style QCs were based u[on).

Here is what they recommend for dual-tapered pinion bearings:

After pinion is installed and case has cooled down to room
temperature (68-72°F), torque the pinion retainer bolts to 25 Ft- Lbs.
Preload New pinion bearings, 20 In- Lbs max
Preload Used bearings to 8-10 In- Lbs

They show two different preload settings for new versus used bearings. I will be using a higher value (probably 15 in-lbs) in my situation (as I have new original bearings).

[JSeery]

Finally found it! Well, found it but can't get it to upload. Here is the link to the web site: http://www.santaanitaas.org/wp-conte...vised-2014.pdf

Note: Forget the 600w gear oil advice at the end, that is Model A stuff and not even correct there IMO, but whatever. Ford recommended (from 1938 Reference Manual) mild extreme pressure gear oil. In todays terms that would be GL-4 gear oil. SAE 90 or 110 winter & SAE 160 summer or SAE 90 or 110 all seasons. In todays gear oil I would suggest a multi-viscosity gear lube. Something like a 75w-140 would be an example or 85w-90.

A mild Extreme Pressure (EP) gear lubricate is required in the transmissions because of the "yellow" metal components. In the rear axle you can use GL-5 if you want, but it might be simpler to keep the transmission and rear axle lubricates the same.

[PeteVS]

I redid a later banjo rear and the gaskets were giving me fits! They were a bit undersize on the ID and were tearing when I tried to get them over the raised lip on the face of the axle housings. I decided to cut up a few gaskets into "two hole" segments and use them for setting the carrier bearing preload. Once that was determined, I used guide pins and Indian Head to cement the "final" gaskets to the faces of the banjo casting. When the Indian Head dried, I used a utility knife with a new blade to trim the ID of the gaskets to the ID of the banjo casting.