MG Sports Cars

i'm in the process of converting to a v8 and am considering my rear axle options. I am aware i could stick with the original B axle and just regear it, however i hear they're not particuarily strong, and ideally i'd like something a bit wider to fill my omni fender flares.
The MG C axle would seem to fill this criteria, however what with the limited production and age of the model finding an axle that doesnt come complete with car (and thus £££'s) is proving very difficult.
I know that most of you US guys are using the S-10 or Ford 8" but the problem is im based in the UK. I was wondering whether anyone might know whether either of these axles were used in any cars that might be found in Europe??

....and not to push my luck but if anyone could name a model which would come complete with a limited slip diff. it would be a lovely little bonus!

thanks as always.

>forgot to mention am running an SD1 transmission. not sure as to whether this may make a difference as to compatability with the diff.



Edited 1 time(s). Last edit at 04/05/2009 06:49PM by andoni10.

The good news is that an original Salisbury axle is plenty strong for 95 percent (or more) of Rover V8 / MGB engine swaps. MGC's have Salisbury axles, just like MGB. Besides cost and scarcity, there's another big problem with MGC axles: most of them came with splined hubs and spoke wheels. (Yuch!!!)

If you're still interested in American axle options... you might want to keep the Ford "8.8" axle in mind too. The Ford 8 inch has been out of production for a long time, but the 8.8 was used on lots of 1990's models. Did the UK market get any of Ford's small trucks or SUV models in the 1990s? (Ford Ranger pickup truck?) If so, I would think they would probably have an 8.8 (with TractionLok limited slip differential) that could be narrowed.

Axle to transmission compatibility is NOT an issue. Whatever you do, you'll need a custom or at least modified prop shaft (a.k.a. "driveshaft"). If you manage to find a suitable axle in the wrecking yard, ask them to include the driveshaft too. You probably won't have to pay much if anything for it. Its yoke can be used by the shop that fabs and balances your new, custom prop shaft.

cheers curtis.

Glad to hear the saliburys up to scratch in case i cant find an alternate axle.
I looked into it and it turns out they're have been Rangers over here although i cant recall ever having seen one. Will have a look around the scapyards. What were more common were Explorers which also seem to have the 8.8.
I know the Explorer axles are slightly different to the Rangers. (The Explorer has 31 spline, and is larger in diameter at the outer bearing journal and has larger diameter bearings.)
You'll have to excuse my ignorance with these next few questions...
Should the differences with the Explorer axle make them any less compatible with the MG?
What modifications would i need to make in order to use the disc brakes from the ford axle?
When shortening the axle will simply rewelding be strong enough?

thanks.

When you're shopping for a donor axle, check for axle ID tags. If you research in advance and figure out what ID codes to look for, you should be able to identify gear ratios and differential types right from the stamped metal tags. Your tranny ratios, your engine's camshaft, tire size selection, and to some extent personal preference will all affect your gear ratio preference. (I ended up with 3.27:1...)

I'm told that cutting and welding the axle housing tubes isn't a technical challenge, but everything needs to be held straight by a heavy bar up the center or by some other sort of fixture. If you call around, there's probably some hot-rod shop near you that does this job all the time.

Are you keeping leaf springs? The same shop will weld new leaf spring perches on your axle. Have them put pins for the rebound straps on too. My local shop installed the perches a bit rotated from the ideal angle, so I bought aluminum wedges to get the pinion angle just right.

This photo shows a spring perch, and if you look carefully you can see where the narrowed tube has been welded-up. (The weld is centered under the perch.)

more info/tips here: [www.britishv8.org]

Are you going to run a rear anti-sway bar? Most people don't... but if you're going to, now would be the time to add brackets for one. If I were you, I'd probably also have the hot rod shop weld on a nice Panhard rod bracket.

Some people shorten and re-spline the actual driveshafts... but I would strongly advise you to just order new ones. In the U.S., the biggest supplier of custom driveshafts is probably "Moser Engineering" (and I can personally recommend them.) Another option is "Currie". You might want to visit their respective websites. When you order new shafts, you can spec whatever lug pattern you like.

Measure carefully! When I had my axle narrowed, I made it a half inch or so too wide. It has worked fine for years, but that extra little bit of width gave me extra headaches when I wanted wider wheels/tires. (Also, I think when you measure your MGB axle you'll find out the pinion isn't perfectly centered relative to the springs. The factory's jig was made wrong. You can correct that on your axle.) If in doubt, make it a little narrower because you can add spacers easier than removing metal.

You'll need new U-bolts, and they'll probably be one size bigger than stock MGB. (You'll have to drill the mating plate holes bigger to accept the U-bolts.)

With regard to the disc brakes... they should be okay, but you'll want to double check in advance that they're not going to interfere with the leaf springs. Don't forget to check the parking brake cable/mechanism.

Now that I think about it, narrowing an axle sounds like a lot of work! I had fun messing with this stuff, and it actually came together pretty quick. As I recall, the total cost (including reworking the prop shaft) came in way under $1500. It was certainly worth it to me.

curtis thats brilliant. thanks a lot. i've managed to locate a ranger axle so hopefully you'll see the fruits of your info up on 'how it was done' in the not too distant future.
thanks again.

hello there.

i too am considering converting to a ford axle. My only concern is that is whether it would be possible to do this and retain leaf springs. My understanding is that for the springs to be as effective as possible they need to be located as close to the ends of the axle as possible; this would mean having to move the leaf spring attachments on the body.

What i was wondering is just how big a job this would be? Is where the mounts are currently located a particuarly strong point on the body? would i need to reinforce the new further outward location?

thanks.

Jim, you wouldn't want to move the leaf spring mounts on the body. That'd be a big job... plus there's not really a wider spot to relocate them to. When you get the Ford axle you're going to have it narrowed so you'd get the spring perches removed & replacements welded on to line up with the stock locations on the body like Curtis noted above. Even if you make your rear axle a few inches wider, you'd still want to do it that way.

I was curious about axle tags and what gear ratios one might find in the truck and SUV models, so I "Googled" and discovered this really cool page: [www.therangerstation.com]

Selecting the correct axle is an important part of the vehicle performance via the the trans and differential gear ratio.
I have a simple spread sheet that will help you determine the correct gear ratio to the transmission ratios and tire dia. which should also be matched to the cam rpm data sheet. This will make a the difference between a nice performer and a slug.

Comparing the Camaro/Firebird gearing and trying to match the OEM gear ratios is not as difficult as it may seem.
The most common gearing for the F body cars with a V6 and very similar to the V8's.

V8's use the 2.95 first gear 1.94, 1.34,1.0 and .63 and some had .73 (GM) final gear ratio 3.08 there were optional gearing such as 3.42 and 3.73 LT special order HO package.

The V6 used the 3.23 with 3 different transmissions one had the 4.03, 2.37,1.49,1.0 and .76 the early V6's used a 3.50, 2.14,1.36, 1.0 and .78 and they also used the 3.76, 2.18, 1.42, 1.0 and .72 with a tire dia of 25.5 still in use with 3.8 V6 Camaro.
With a combination of tire dia and final gear ratio the mph can be matched to between 2-3 mph of each other by just changing the final gear ratio and tire dia, regardless of which trans you choose. The choices are 3.55 Ford, 3.23 and 3.08
The 3.08 couple to one of the most common transmisions which is the 4.03 first gear with a 23.5 tire dia (MGB) is 1 mile slower in all of the gears except 5 which is 6 mph faster than the 3.5 first gear and 3.23 final ratio, at a 2400 rpm in all of the gears.

my wife and I did a spread sheet that can help you compare 6 combinations at the same time. The rpm is for a stock factory camshaft which cruises at 1800 to 3000 rpm red-line to 5500 to 6000. A performance camshaft can be from 2400 to 3500 which meand crusing rpm should be around 2600 for best performance in the hwy.
If you want the spread sheet e-mail me at regualr e-mail.

True. Bill's full contact info is here: [www.britishv8.org]

and the basics are here:


Dan Masters' gear ratio calculator (in Excel spreadsheet format) is here on the BritishV8 server: [www.britishv8.org]

nice one guys. thats all really helpful.
bill that spread sheet sounds just the ticket if its not too much trouble. i'll send you an email. thanks

You might take a look at the following "banjo" style axles... they make changing rear end ratios much easier:

79-85 Mazda Rx7.. some of the later ones (GTU and GSL-SE models) have disc brakes (including parking brake function) and limited slip.

same era Toytota Celica/Corolla/pickup... again, some (GTS, etc) have disc brakes and/or limited slip. Lots of ratios available.

They would be good for 4 and V6. They have a 7.5" ring gear.Most common ratios for Mazda RX7 is 3.91(same as MGB) and 4.10. Some passenger cars had 3.31 but rare.Celica is a little better 3.73,3.91 some 3.54 and 3.32 if you can find them (probably in Automatic cars. I think they are still a couple inches wide. You could use FWD wheels with spacers in front. Some years had rear disc brakes. They have 4 link and panhard or watts linkage suspension which would be interesting to modify for the MGB. Another similar axle is found in mid 80's Dodge Colt and Plymouth Sapporo (Mitsubishi Gallant).



Edited 3 time(s). Last edit at 07/10/2009 05:47PM by mgb260.