Thread: 9 inch ford rear end

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I HAVE A 1976 MERC COUGER XR7 REAR 9" WILL IT FIT IN A 1941 FORD WITHOUT CUT DOWN

http://www.teufert.net/other/rear%20...dimensions.htm

speaking of 9" ford rears, should new gear sets NOT be broken in with synthetic oil like they say for engines, or is it good to break in gears with synthetic.
Also, when installing the axles, once the splines engage should the bearings be tapped into place with a little hammer on the end of the axle, or should they be drawn on with the retainer plate bolts?
Also, should any grease or sealer be smeared around the outer race beforehand or do those suckers go in dry?

Originally posted by tcodi
speaking of 9" ford rears,
1. should new gear sets NOT be broken in with synthetic oil like they say for engines, or is it good to break in gears with synthetic.
2. Also, when installing the axles, once the splines engage should the bearings be tapped into place with a little hammer on the end of the axle, or should they be drawn on with the retainer plate bolts?
3. Also, should any grease or sealer be smeared around the outer race beforehand or do those suckers go in dry?

Does anyone have any thoughts on any of these questions?
The people at Currie told me I should never use synthetic gear oil in my 9" Trac Lock, do you agree?

Nothing like reviving a year old thread.

I'll put amsoil in anything I have. Might need an additive for the clutches as you would with reg. oil. Tap the wheel bearing in with a hammer, don't pull it in with the retainer or you will bend it. Clean the outside of the bearing and it don't make no dif if you grease it or not, it don't do anything.

Originally posted by Randall
Does anyone have any thoughts on any of these questions?
The people at Currie told me I should never use synthetic gear oil in my 9" Trac Lock, do you agree?

Nothing like reviving a year old thread.

I was reading through BDS and they mentioned that synthetic oils are just too thin to use with thier blowers. Granted, you're not using this on a blower, I would think these gears would be subject to the same type of load as the blower would be, so I would agree with the people from Currie.

Originally posted by RJ & CJ
I was reading through BDS and they mentioned that synthetic oils are just too thin to use with thier blowers. Granted, you're not using this on a blower, I would think these gears would be subject to the same type of load as the blower would be, so I would agree with the people from Currie.

Amsoil has the best #'s of any oil. reg. oil wouldn't stay in the first jets so a synthetic oil was made so they could fly those things, but its not good enough for a blower? i would think a 50 or 90W in oil or synthetic would be the same thing. i've run it in everything i had and still do. sounds like BDS must own some oil stock.
https://www.amsoil.com/storefront/svo.aspx

deking, I have a 73 Mustang 9" under my 46 Ford Cpe. Fits good. Joe

AMSOIL and Break In on New and Rebuilt Engines

Q. I heard that new cars require a break in period with petroleum before you switch them to synthetic. How long should this break in period be?

A. AMSOIL Synthetic Motor Oil can be used during break-in trouble free. In fact, vehicles such as Dodge Viper and Chevrolet Corvette come factory filled with synthetic oil.

I'll probably regret this but since these threads come up for review by people using search engines it helps to clarify some things for posterity.

First, if you look at the chart I linked, you'll see the '76 rear is 2" wider than the '73.

Second, if you're relying on a warantee to be backed by a supplier (perhaps such as the Currie example) you'd be wiser to follow their recommendation rather than trying to beat them in an argument, especially using potentially self serving info from say a lubricant suppliers site. Mike's comment about needing to have or add a friction modifier for the clutches is technically accurate, but you might still lose the argument and not have a manufacturer caused failure paid for. Being right and getting reimbursed are two different things.

Third, that being said some manufacturers may be way off base. RJ, if what you relayed is 100% accurate rather than your best recollection or interpretation, then BDS doesn't understand lubrication very well, or doesn't believe their customers have a clue and are trying to take an easy out. They're pretty bright folks there, so it's hard to believe they are clueless about lubrication. A link to the comment would have been useful in clarifying. Viscosity is measured by an ASTM standard. The test doesn't care whether its a mineral oil or a synthetic. Viscosity is a measure of rate of flow at a specified temperature. As an example, a motor oil with a set of two numbers, e.g. SAE 5w20, means that the oils viscosity is expressed at two temps, 0*F (the W designates winter so flow at low temp is important), and at 210*F. A single grade such as SAE 30 is an expression of the rate of flow at 210*F only. Perhaps BDS is trying to say that a synthetic (multigrade by design) MOTOR OIL, shouldn't be used because of it's light viscosity at low temps which might be insufficient to protect the gears at start up.

Fourth, codi might not have gotten an answer originally because his question wasn't directly related to the original intent of the thread. Sometimes it's better to start a new thread if your questions aren't exactly related to the original topic.

Lastly, making cross comparisons doesn't always work. For the sake of brevity there are essentially three types of gears; spur, helical, and hypoid. The spur gears have straight teeth and are a rolling motion between the opposing gear teeth, a pretty easy to lube environ, viscosity can handle it entirely (assuming load to gear size design is correct). Helical gears have angled teeth and the tooth interface has a slight amount of sliding action that usually requires an anti-wear additive (dependant on tooth angle, load, etc.) to help protect the teeth. The hypoid gears (typical to rear ends) have a relatively severe twist to the gear teeth which results in the tooth interface experienceing entirely sliding action. This requires an extreme pressure additive to prevent accelerated wear. What works for a spur gear won't work at all for a hypoid.

Blowers typically have spur or helical gears to syncronize/drive the impellers/screws and are nowhere as demanding as a rear end. Very different working conditions without a comparison of wear action. Similarly, the high temperature of a jet engine has no correlation to the operating conditions experienced by a motor oil. It is accurate that synthetics first came into use because of the unique application perameters of the turbine engine, but their impressive performance there doesn't automatically mean they're good in everything.

That being said, I am not arguing that synthetics can't work in an automobile engine. They have some very good performance characteristics that can be useful, especially at very low temperatures. And I don't intend to get into a debate over whether or not someone is crazy to be for or against the use of synthetics versus minerals, it's like religion, make the choice you feel best with. I won't try to convert you, don't try to convert me, whichever way you perceive my bent.

I wasn't trying to convert no one to Amsoil, he asked a? And I gave him my opinion. What BDS is telling him is a bunch of crap, and far as I know you don't have to use what they say or lose the warranty. GM and Ford tried that and lost. a blower on a truck lub. with motor oil, and run for hrs. without a problem. its a fact Amsoil has the best # of any motor oil, in all catalogers, but that's not the reason I use it, I have a friend in Rich. that drinks it for dinner, and I buy it from him to help him out and I believe its a good oil. I've used more Pennzoil than anything. I'd start with whatever they wanted me to and then change it sometimes later if i wanted to.