Lowering a Rubber Bumper MG

[usasma]

I've read that MG had to raise the MGB's 1.5 inches to comply with the US governments requirements when it added rubber bumpers.

Is there a site/instructions on how to lower the car back to it's original height? Or, is there a site/description that describes exactly what modifications were made to raise them (so that I could reverse it)?

I remember the handling of my earlier MG and miss that feeling in my new rubber bumper baby!

Thanks, in advance!

 

[Bret]

Just completed lowering my 78B’s suspension – 2” up front & 1.5” in the rear. Now to answer you’re question I don’t know all of the changes done to make them comply with the US DOT. But the main item they changed was the front cross member. Many folks with tell you that that is the first thing you’ll need change if you want to go back to chrome bumper ride hight.

While some might say that is the best way to do it – I regrettably didn’t go that route – opting for aftermarket options. Lowering springs in the front & rear saw the hugest improvement, along with a complete set of Poly bushings and a few other changes. For full details of what I did, feel free to checkout my web pages:
https://home.earthlink.net/~bretduff/id8.html

Another consideration is what year Rubber Bumper B do you own? If it’s one of the first couple years you have a worst problem than I had to contend with. Because in MG’s haste to raise the ride height, they seriously hampered the handling more so than they originally figured I’d bet. Anyway in an effort to correct this, they added an additional rear sway bar later in production. While this helped – it still wasn’t a cure all to the problem.

As for my suspension project - I think it turned out alright. Lowering the Rubber Bumper B will really improve the feel & handling.

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[bobmga62]

I noticed Moss had a way of converting a high-rise rubber bumper MGB to chrome bumpers... unfortunately, still leaving the car high and dry.. why bother!

Actually, probably the most efficient way to lower your MGB, is just simply install, a whole new cross member form an earlier B... in essence, other than brake lines and steering arm, its just four big bolts that hold the whole unit on..

I still have a complete unit in the spares pile if I ever need it, and I have seen the complete units (to include springs, shocks, brakes, clibars, discs for small money on e bay..

In essence I don't know what they did to the back, but probably the easy way (not necessary the best solution) is just put a block of steel between the axle and the springs (watch the length of the spring u bolts though)

Many years ago I lowered my G-Producton MGA by de-arching the rear leaf spring... again a real cheap solution...

As mentioned in an earlier thread though, you'll have to do all new alignments etc. etc.

Between you and I, if I had no other choice than a B High-Rise... I'd lower it immediately!

good luck

R

 

[usasma]

I'm going to lower it, that's a given (it's a 1974½ B-GT) and am considering adding anti-sway bars front and rear. It sounds like the lowering the front will be pretty straight-forward. I'm still concerned about the rear tho' - I'll probably end up checking out the local club's cars to see if there's any obvious difference - and if they've got any info on the conversion.

Oh well, it's a labor of love! Thanks for the advice!

 

[Bret]

Just some thoughts to add to my previous post.

Old Crossmembers?: /ubbthreads/images/graemlins/confused.gif While I didn’t do this, an old Crossmember is probably the best way to lower the front end. But you should know that I used up-rated lowering (2”) springs and poly bushings and am happy with the results. That said – if you can find good used cross-member - go for it. But if not - you have some other cheaper/easy options to consider too.

Sway-bars?: The front sway bar should be a simple deal to up grade. All kinds of kits out there that will have everything you need to do this. The rear however is an altogether different animal and isn’t really recommended for earlier cars, according to Moss. But should your heart be set on this - its going to require a bit of fabrication to link sway bar to the axle and the SB end fittings to hard points of the chassis. I’d seriously re-think this if this is what you really want to do.
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Rear Springs re-arching!?!: /ubbthreads/images/graemlins/nonod.gif While I’ve never tried this - Other than saving a few bucks($), I’ve heard noting good about re-arching leaf springs. “They don’t last” – being the biggest complaint I hear the most. The other thing to keep in mind is why bother re-arching a tired 30 year old set of leaf springs, when you can spend a little more and get a brand new set of stock or lowered springs for between $125 & $150. I replaced both of my rear springs with stock and added lowering blocks to achieve the ride height I was looking for and am really satisfied with the results..

Good luck!
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[Baxter]

I've had very good luck with re-arched/de-arched leaf springs... typically this is done on heavy trucks, so MG springs are child's play to those guys. Considering the haphazard controls I've heard of on the new ones, I'd definitely look at re-arching again.

As for lowering the front, I'm in the camp that believes swapping the x-member is the best way to do it, especially if you want the ride/handling balance of the early ones.
BUT... you also have to swap the steering rack, or modify the pinion shaft, to make it all hook up. When I did mine I needed a steering rack anyway, and I picked up a x-member cheap, so it was no big deal. If you have to pay dearly for both, it can get real expensive fast.
And if that's the case, your other options are lowered spindles (no personal experience, but I hear they're good, and don't mess up the geometry) or lowering springs, which will give a harsher ride and allow less spring travel, but that may not be a problem for you.

 

[Bret]

[ QUOTE ]
I've had very good luck with re-arched/de-arched leaf springs... typically this is done on heavy trucks, so MG springs are child's play to those guys. Considering the haphazard controls I've heard of on the new ones, I'd definitely look at re-arching again.

<<SNIP>>

[/ QUOTE ]

In fairness - I’m only going with second hand info & have no personal experience with re-arching either. Fact is, I actually considered re-arching my old springs when I was re-building my rear suspension (poly bushings, shackles & all new hardware etc.). While I'm of the view that this might work well with newer or better condition springs, I don’t think it would be a good idea for older beat-up units.

In my car’s case the leaf springs (by my assessment) were so far gone & totally shot, that I didn’t want to waste my money. Heck, laying them side by side one was far worst (flatter) than the other. Seems like a great waste of money to re-arch some 25 year old tired springs – when I can order new ones and be reasonably sure what I’m getting.

But hey, I’ve been wrong before so if somebody feels differently, I still have the old springs and would gladly “give” them to you to prove me wrong. All I ask is that you pay shipping or pick them up yourself.

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[Baxter]

And in all fairness, I coulda just got lucky. The place I took mine really knew what they were doing, and I'm fairly sure they woulda sent me packing if they couldn't be re-arched and work.
There's definitely a point at which you can't re-arch them, or you'd be foolish to try.
I've heard a lot of problems with new ones having incorrect arches, incorrect rates, wrong springs being sent altogether, and so on, so I guess either way you pays yer money and takes yer chances.

 

[Bret]

[ QUOTE ]
<<SNIP>> new ones having incorrect arches, incorrect rates, wrong springs being sent altogether, and so on, so I guess either way you pays yer money and takes yer chances.

[/ QUOTE ]

Agreed. But (this is just a guess, mind you) then obviously one would have to assume that if there is a problem (like you discribed) after purchasing a set of “new” leaf springs, you'd have a better chance of getting some sort of compensation (ie money back) than you would if you paid someone to re-arch a set of older springs that didn’t work out.
/ubbthreads/images/graemlins/rolleyes.gif

Another up-side (IMHO) to replacing older springs with new ones rather than re-arching. Is that you can exchange them the day you take delivery. Where to re-arch would (I’d assume) would require some time on a set of blocks or jack-stands while you wait for the process to be performed.
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