The Triumph Dolomite Club - Discussion Forum

Hey guys, long time since i posted, been busy moving house.

has anyone ever fitted, or been temped to fit, an MG B GT axle for its strength

after some research online, there were 2 types, "Banjo" and "Tube"

the Tube type was used in all GTs, including the V8s, and on some of the MG forums, they say about 300hp is possible before there are issues with spider gears.

i only bring this up as i want to fit a larger engine to my 1500, a Jag v6 to be precise, but could find an axle thats narrow enough.

the rear track width on the MG B GT is similar, if not an inch narrower, than the Dolomites, which would be handy if you wanted to run a hot V8 without having to run wide arch kits and truck axles

anyways, just putting it out there

Max

You'll destroy the half shafts way before you get to 300bhp.

As a long term MGB V8 owner, I can say that the Salisbury tube axle is a strong unit. It can certainly handle 200 bhp and 200 lb.ft torque as it is fitted to the RV8 and several owners have upgraded their 3.9 litre engines to over that amount. I have never heard of a half shaft failure on this axle. There was a guy called Perry Stephenson who used to drag race his V8 complete with full nitrous kit. He was getting down to 11 seconds for the quarter mile and was using that axle as far as I know. I can't say what the maximum load would be, or whether it can handle 300 bhp. I'll post a question on the MGCC V8 Register board if you like.

Sprint axle bolts straight in

Tony

SprintMWU773V wrote: ↑Tue May 30, 2017 3:07 pm You'll destroy the half shafts way before you get to 300bhp.

Reading up on the MG forums, the weak point at 300hp is the spider gear, then half shafts. When you change to LSD, you remove the spider gear, making it stronger. The Tube axle is a Sailsbury Axle, which is used in Defenders and other off-roadrrs. It's know to be quite strong

Bumpa wrote: ↑Tue May 30, 2017 3:57 pm As a long term MGB V8 owner, I can say that the Salisbury tube axle is a strong unit. It can certainly handle 200 bhp and 200 lb.ft torque as it is fitted to the RV8 and several owners have upgraded their 3.9 litre engines to over that amount. I have never heard of a half shaft failure on this axle. There was a guy called Perry Stephenson who used to drag race his V8 complete with full nitrous kit. He was getting down to 11 seconds for the quarter mile and was using that axle as far as I know. I can't say what the maximum load would be, or whether it can handle 300 bhp. I'll post a question on the MGCC V8 Register board if you like.

I quote the 300hp limit from a MG forum (I forgot which one) after googling for MGB GT axle strength.

But thank you for asking.

tony g wrote: ↑Tue May 30, 2017 3:59 pm Sprint axle bolts straight in

Tony

i asked last time if a sprint axle would work, was told would handle the power, but not the torque of the Mighty Jag V6. in stock form, its 230hp/300Nm.

Bumpa wrote: ↑Tue May 30, 2017 3:57 pm I have never heard of a half shaft failure on this axle.

I've lost count of the number of broken shafts I've seen on track cars, it's usually followed by the loss of a wheel with what's left of the shaft!

Maybe if you had full torque on slicks you may get a a prob but on treads youll probably spin the tyres. Get it running and see what breaks or youll spend all your life trying to re-engineer things that you maybe dont need to

Tony

Boost All The Dollys wrote: ↑Tue May 30, 2017 4:02 pm

Bumpa wrote: ↑Tue May 30, 2017 3:57 pm As a long term MGB V8 owner, I can say that the Salisbury tube axle is a strong unit. It can certainly handle 200 bhp and 200 lb.ft torque as it is fitted to the RV8 and several owners have upgraded their 3.9 litre engines to over that amount. I have never heard of a half shaft failure on this axle. There was a guy called Perry Stephenson who used to drag race his V8 complete with full nitrous kit. He was getting down to 11 seconds for the quarter mile and was using that axle as far as I know. I can't say what the maximum load would be, or whether it can handle 300 bhp. I'll post a question on the MGCC V8 Register board if you like.

I quote the 300hp limit from a MG forum (I forgot which one) after googling for MGB GT axle strength.

But thank you for asking.

tony g wrote: ↑Tue May 30, 2017 3:59 pm Sprint axle bolts straight in

Tony

i asked last time if a sprint axle would work, was told would handle the power, but not the torque of the Mighty Jag V6. in stock form, its 230hp/300Nm.

tony g wrote: ↑Tue May 30, 2017 4:26 pm Maybe if you had full torque on slicks you may get a a prob but on treads youll probably spin the tyres. Get it running and see what breaks or youll spend all your life trying to re-engineer things that you maybe dont need to

Tony

Fair enough Tony, i just want to spend my money wisely, and not have things brake. this axle just seams like the best opportunity to have a high horsepower Dolomite that is a total sleeper. its difficult to find high torque axles that are narrow enough to fit under the Dolomites 50" track width. these axles are cheap and reasonably strong, i don't want to be putting a sprint axle in for it to detonate 5 minutes in, its both a waste of money and a good sprint diff.

seeing as people run decent (high) power through these diffs, it would hold up to the posibility of some small mods to the engine. if i wanted 300hp, i wouldnt have to change axles, saving money and time. plus the ratios are very similar to what i already have, 3.89 vs 3.9

Yes, the 'BGT tube axle is strong for 98bhp. Mine is on 185,000 with a standard 1789 engine. But parts are getting scarce now. If you are doing a Jaguar engine conversion the usual diff; to fit is the Salisbury IRS one. The Lotus unit is very strong ( as fitted to the Elite / Eclat with up to 165bhp from the 912 unit ) but you have to put up with the rear drums. The similar diff; from the XJS is also good but you get rear discs. Then you only have to worry about drive shafts and suspension. And a suitable prop; shaft of course. A suitable Jaguar / Lotus drive line would be a start.
Tony.

MIG Wielder wrote: ↑Tue May 30, 2017 9:23 pm Yes, the 'BGT tube axle is strong for 98bhp. Mine is on 185,000 with a standard 1789 engine. But parts are getting scarce now. If you are doing a Jaguar engine conversion the usual diff; to fit is the Salisbury IRS one. The Lotus unit is very strong ( as fitted to the Elite / Eclat with up to 165bhp from the 912 unit ) but you have to put up with the rear drums. The similar diff; from the XJS is also good but you get rear discs. Then you only have to worry about drive shafts and suspension. And a suitable prop; shaft of course. A suitable Jaguar / Lotus drive line would be a start.
Tony.

The tube axle is what they use on the GTV8 so I'd say it's very strong. The Banjo axle is apparently very weak as the case buckles and bends

Apparently the Reliant Scimitar GTE axle is well though of for strength and endurance. Just a thought!

I would have thought you'd need a taller diff than the 3.9 behind that Jag motor - or you'll have wheelspin is the first 4 gears at least!

Steve

It is the 4HA axle. That is under the scimitar, old jag mk2 and many others. This axle was also used by some works teams. The talbot lotus gp4 had this axle and i thought some opel/vauxhals also.

Jeroen

Carledo wrote: ↑Tue May 30, 2017 11:52 pm Apparently the Reliant Scimitar GTE axle is well though of for strength and endurance. Just a thought!

I would have thought you'd need a taller diff than the 3.9 behind that Jag motor - or you'll have wheelspin is the first 4 gears at least!

Steve

The GTV8 ratio is a cool 3.07, but that's quite expensive and rare to find an original example of. I'm sure there is a aftermarket CW&P that's a better ratio

Boost All The Dollys wrote: ↑Wed May 31, 2017 6:35 am

Carledo wrote: ↑Tue May 30, 2017 11:52 pm Apparently the Reliant Scimitar GTE axle is well though of for strength and endurance. Just a thought!

I would have thought you'd need a taller diff than the 3.9 behind that Jag motor - or you'll have wheelspin is the first 4 gears at least!

Steve

The GTV8 ratio is a cool 3.07, but that's quite expensive and rare to find an original example of. I'm sure there is a aftermarket CW&P that's a better ratio

That'll be the same as a TR8 then, which is also available with an LSD, has similar mounts to a Dolomite and is only a couple of inches wider. Not cheap though, the last one I saw with LSD and disc rear brakes was £800.

Steve