7 inch or 7.5

[Sunnysidebb]

Is there a quick way of visually checking if your rear diff is 7 or 7.5 inch.
eg shafts a different length etc.

Secondly is there a good place to buy a complete set of rear beam and diff bolts. Just completely stripped mine and the bolts are well manky.

Thirdly, where is the best place to get a 6 deg beam. Im not sure if its one for one exchange they will want mine as they are....to say the least in poor shape. I was going to media blast mine and paint them but Im not sure how much yhey have been compromised by corrosion so perhaps now is the time for a 6deg set up.
Thanks
Frank

[Cochyn]

SCS or Anembo (who make them using MK Motorsport specs now) for a beam and there are full bolt sets for cossies on eBay. But you can go to an engineering supplies shop and buy stainless high tensile Cap head bolts that are much cheaper. I get mine from Brabbins and Rudd in Bolton. Any size and thread.

[Sunnysidebb]

SCS or Anembo (who make them using MK Motorsport specs now) for a beam and there are full bolt sets for cossies on eBay. But you can go to an engineering supplies shop and buy stainless high tensile Cap head bolts that are much cheaper. I get mine from Brabbins and Rudd in Bolton. Any size and thread.

Thank you. We have a great place local for bolts etc.
Does a 6 deg beam make the car intrinsically safer or does it remove any inbuilt safety Ford designed in to it.
Car is on fully adjustable coil overs and apart from the usual mortgage sum Ive spent on her she has a MAD Mark 500+ set up . I'm no race driver and my National A rally licenced expired 20 years ago so Im getting old and slower reaction. I dont want it to be easier to get in to trouble with the 6deg set up???

Will give Jimbo a call next week about beam if you think it helps safety.

[c20tbo]

Frank, measuring the diff width across top bolt hole area with give you diff size, Anembo for beam and ebay for bolt set

An LSD 7.5" diff driveshaft output flanges will be 108mm also not 100mm as in 7"

[KR54321]

Frank, beware of stainless bolts, as these are weak. Can be used for thermostat housing, not for suspension or brakes.

Also don't measure the flanges as most of 7,5 diffs use 100mm flanges, same dimension as 7,0 inch.

Good way to check is to look if the diff has two long bolts (one at the bottom, other at the top of the diff) going through it to mount it in the beam. 7.5" diff has only one long bolt at the bottom and instead of the long top one, uses two short bolts from both sides for the top mounting.

[Wing Commander]

Frank
i would mirror the comments about stainless above. These fixings are important!
I had a great experience with my 6 degree beam from OMS . The modification to my beam allows for the larger diff . It comes with with a spacer to allow for fitment of the standard diff . I would imagine Sierras R us would have a donor beam
looking forward to driving my car with better handling

[Grand Tomismo]

Just to add, the ratios of the differentials are different,

4x4 - 7" is 3.62 : 1
2wd - 7.5" is 3.64 : 1

Not a massive difference, but if you are staying 4x4 and change to the 7.5", there is a chance that over time the ratio difference could start to damage to gearbox viscous coupling as its not designed for a mis-match in ratios.

[twin turbo]

Look on rear cover 7.5 have alittle "cutout" in lower corner, quickest way too see if 7 or 7.5

[Cochyn]

Frank,

Highly disagree with the stainless comments. Stainless are fine if they are high tensile graded. I’ve been running them on my car for 13 years on a 6 degree beam and rose joints throughout the car, completed a Gatebil (Norway) trip and 16 Nurburgring trips and counting so far with zero issues. I use my car as intended. I advise buying them from a proper engineering firm instead of the eBay kits, because you can specify exact grade and lengths you require. Plus the cost aspects is a big bonus.

In terms of the 6 degree beam, it doesn’t stop the inevitable over steer cossies are known for, but you can control the snappy reaction and regain stability much more efficiently. Straight line launches you’ll find traction to be more consistent and the back end generally feels more planted. All benefits of having the wheels 3 way adjustable on solid rose joints that don’t flex like bushes do, so much safer than ford designed. There are a few companies that make them now, very much the same all round. Some look fancier than others but generally do the same things. But the MK (Anembo) and SCS are the most tried and tested.

[KR54321]

Interesting read.
So please give some details - what are the grades of the stainless bolts you use. What is the material they are made of? Regarding stailnless, it is usually stamped on the element.

[Cochyn]

If you have general HT steel bolts, they would tend to be 8.8-10.9. Stock stainless are A2 graded and when exposed to salt will result in chloride stress corrosion, whereas A4-80 are marine/aircraft graded and even off-road Land Rover firms sell them. I’ve smashed 2 bolts in a vice a few years ago of roughly same age, 1 steel 10.9 and 1 stainless A4-80 and the steel always bends and snaps whereas the A4 bends with great force but didn’t snap.

These are my findings really and not gospel, but I’ve looked into it a long time ago and this is purely what I remember off the top of my head. The proofs in the pudding with continued use and level of abuse. I think I’ve tested them effectively lol

[Sunnysidebb]

This site always amazes me with the wealth of information. With an expensive item such as a 6deg beam its always best to get a consensus.
A call to SCS Monday is on the cards.
.

[Sunnysidebb]

If you have general HT steel bolts, they would tend to be 8.8-10.9. Stock stainless are A2 graded and when exposed to salt will result in chloride stress corrosion, whereas A4-80 are marine/aircraft graded. I’ve smashed 2 bolts in a vice a few years ago of roughly same age, 1 steel 10.9 and 1 stainless A4-80 and the steel always bends and snaps whereas the A4 bends with great force but didn’t snap.

These are my findings really and not gospel, but I’ve looked into it a long time ago and this is purely what I remember off the top of my head. The proofs in the pudding with continued use and level of abuse. I think I’ve tested them effectively lol

I agree stainless is not as bad as some people think when it comes to strength. We had them everywhere under the casing of Submarines. The biggest issue was Galling of the thread. Than can be illiminated by not over tightning and not using high speed air driven tools. By hand nice and easy.

[Cochyn]

I agree stainless is not as bad as some people think when it comes to strength. We had them everywhere under the casing of Submarines. The biggest issue was Galling of the thread. Than can be illiminated by not over tightning and not using high speed air driven tools. By hand nice and easy.

Aye, I always do them by hand anyways. But you can ensure that’s avoided by using same grade Lock nuts too and appropriate grease.

[KR54321]

I thought so. ;-)
The A2 and A4 steel parameters disqualify them from using for suspension / brake system, as parameters of these materials make class of the element lower than the standard steel 8.8 grade bolts.
I'd take care of my own safety even if you visit Nurburgring only on Playstation, like me.