4 speed manua - overdrive

I

iggy

New Member
hi the 4 speed gearbox in my car in my car needs to come out its very noisey, so i im trying to find out if the mgbgt v8 overdrive gear box will fit, has any one fitted one to there car?
 
It will obviously fit to the engine, the rest will just be clearance in the tunnel. I've not heard of it being done, so the only way to get some idea would be to start measuring up.

Depending on when you get the noise the 3500S can be a fairly easy fix, so don't write it off straight away.

I'd go for an LT77 or R380 5-speed rather than an overdrive as they can be unreliable.
 
We have a couple of BV8 experienced members on here so can they pass some comment on how reliable the BV8 box is. I had both a BV8 and an MGC, both with overdrive and would confirm the combination makes for a very nice drive. BUT the C eat it's gerabox in spectacular fashion and I understood at the time that that was quite common. AND it was hugely expensive to fix as the C box shared little in common with the B and was extremely obsolete. I always understood the box in the BV8 was a straight hand me down from the C with a revised bell housing to suit the V8.

The overdrive I really liked (and on P4 Rovers), but I didn't think it was that expensive to fix as basically all overdrives are the same - so there are a reasonable number of bits around.

My recollection of the box in the C (we had a large engine incident as well) was that it was pretty huge. I would'nt have thought it would have fitted in a P6 manual tunnel. Like the LT77 and R 380 (basically the R380 is a next generation version of the LT77 and to be found cheaply in life expired LDV Sherpas) I would have thought you would have needed to graft in the transmission tunnel from an auto shell. A 4 cylinder will do as the tunnels are the same. And there are a lot of unwanted 4 cyl autos to be found lying around with rusted out sills and floors but the tunnel OK.

Chris
 
Talking about gearbox conversions, now that i have the replacement engine and gearbox sitting patiently in my porch waiting for the hoist, i can see that i would be fairly easy (OK i will not bet) to make an end plate identical to the one bolted to the 4 cyl engine, but with a new hole arangement that will suit the replacement gearbox. Tunnel clearence problems have been discussed, but what on earth do you do with the input shaft? Do you get away by using the clutch plate from the new gearbox? If it is the same diameter as the old one can someone assume that you can retain your old clutch cover and flywheel?
Not that i am going to start anything now, just food for thought...

Demetris



Edited By Demetris on 1210599017
 
If the clutches are the same diameter you can use the centre plate to match the g/box, and the cover plate to fit the engine, but this is only a general rule, as fitting the LT77 to the P6V8 requires both parts that come from the g/box (SD1).

Another way is to use the centre and pressure plates to match the gearbox and have the flywheel re-drilled for the mounting holes. It's not always straightforward as pressure plates can be different heights giving actuation problems, but there are always ways around things.
 
il have to get my gear box checked by some one with more experience than me, it does make alot of noise in all gears but slightly less in top gear, i have found acompany in rugby that makes and suplies overdrive units to fit any rear wheel drive car providing theres enough room behind the box
 
iggy said:
il have to get my gear box checked by some one with more experience than me, it does make alot of noise in all gears but slightly less in top gear,
Click to expand...
having done a few (hundred ! :D ) "S" boxes if it's noisy at standstill with your foot off the clutch it's the 1st motion shaft bearing, if it's only on the move and worst in 1st 2nd & 3rd it's the rear mainshaft bearing, which is sadly NLA new, but a good secondhand will do, or an alternate bearing with a machined sleeve can be fitted.

Needs a good test driver, and for definate diagnosis, dismantling and inspection.
 
iggy said:
il have to get my gear box checked by some one with more experience than me, it does make alot of noise in all gears but slightly less in top gear, i have found acompany in rugby that makes and suplies overdrive units to fit any rear wheel drive car providing theres enough room behind the box
Click to expand...

Can you post their details please?
 
heres details of o/d spares 10 arches buisness centre mill rd rugby cv21 1qw, tel 01788 540666 e mail odspares@aol.com call david twigger, as i said they dont only sell spares but overdrive conversions for most rear wheel drive cars
 
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