LT77 MGB problem

[tetlow]

I have tried to fit the Engine and new box today.

What a pig, working outside too.

I need a few pointers please.

Engine has a new block and new LT77 box “kit” from the MGOC.
I was led to believe it would be a straight swap for the old 4syncro unit I have been using. It seems not so.

With the engine sitting in the same location as before I have found that:-

1) Box hits the top of the tunnel at the front. ( I have a Rubber bumper shell).

2) Gear lever is about 1" too far forward. (It has a modified remote linkage)

3) The Modified cross member does not match either of the pairs of mounting holes.

The engine cannot go back any further without some bulkhead bashing, and cannot go any lower as it will hit he power steering rack.

Should the bottom of the box be parallel to the ground when fitted correctly? If so it will have to go up a hell of a lot.

I assume I will have to drill new cross member mounting holes and bash the tunnel up a bit and re-cut the hole for the gearlever, or have I missed something!!!

Any recommendations would be appreciated.

Regards

Dave

[davemgb]

Dave,

What year of shell are you working on? There are early and late rubber bumper shells.

When I modified my 1972 car I changed the bulkhead to be a copy of the MGV8 setup with the cutoff corners either side of the heater, which my be the same as you RB shell.

To clear the top of the gearbox I had to cut the bottom of the heater duct and rise it to the height of the tunnel just in front of the gearlever hole - for some reason this is the highest part of the tunnel! Can't remember what angle the box is at and its raining again.

My standard SD1 remote placed the gearlever about 1/4'' back on original position which I live with.

Have you tried turning the gearbox crossmember round - the existing holes have threaded blocks behind them, if you drill fresh holes they have to go through into the car.

This doesn't really help you now but I could trundle up on Saturday to compare notes.

Dave

[tetlow]

Hi Dave

I have a very early Rubber Bumper shell 1975.

I was hoping to drill fresh holes for the crossmember but move the inner threaded block to suit. I might be able to get access to the block from above and weld it up after!!

Do you know if the bottom of the box should be parallel to the ground, Mine will be an angle even if I get it to clear the tunnel.?

Thanks for the offer to come up. I am working this weekend and for the next 10 days but if I can call on you when the $*£% gets too high.

Dave

[JC.]

I put an LT77 into my MGB early last year.

You will need to modify the top of the front of the tunnel to get the box in.
You might be able to get away with dressing it up like I did or you may have to cut it out and weld in a hump.

RE the gearbox X member. Did you realise there are 3 captive nuts per side for the cross member? Make sure you're using the correct ones.

[tetlow]

Hi JC

I will start with a lump hammer first.

Is the front of the tunnel structural? Can I cut a portion out and rivet a new plate in or should it be welded??

What sort of clearance should I have. I was imagining 1/2" would be OK?

The captive nuts for the cross member. I seem to have 4 each side. I thought they were all the same and I had a choice of 2 positions!!

Was the bottom of your box horizontal?

Dave

[CastleMGBV8]

Dave,

The only mod to fit a Rover V8 and SD1 LT77 gearbox into a rubber bumper shell is a mod to the top of the gearbox tunnel directly behind the centre/radio console and a mod to the crossmenber.

You need to cut out a section of the tunnel roof and weld in a small box approx 1" high I don't have the width and length dimensions to hand at the moment but will try and find them for you.

The gearbox crossmember needs modifying with some new mounts for the SD1 box. you have to cut the MG ones off and weld on the new ones.

Dave Vale at V8 conversions 01689 858716 usually has them and will provide a drawing to show how the mod is done, if you talk to him he can provide a drawing for the gearbox tunnel mod as well.

One last thing he says hesitantly (straws and Camels backs) did you change the spigot bush in the end of the crank to match the LT77 box, if not just as well the engines not gone in yet, Real Steel have them.

Kevin.

[CastleMGBV8]

Dave ,

The best way to get the engine and box into a B is to raise the rear of the car on axle stands this improves the angle of the engone and yo the shell and on mine it went straight in and it all bolted together perfectly. you need someone with small fingers to get the nuts and washers on the engine mounts and don't forget the lock plates which stop the engine rotating in the mounts. Another good tip os to fit one spacer washer on the mounting on the steering column side which provides additional clearance to the pinion shaft and I would fit an engine steady bar or your engine mountings won't last very long. Dave Vale should have one in stock and he's cheaper than Wheatley for parts.

Ypu coulsd have a look in the archives on the MG BBS theres lots of info and pictures of the tunnel mods.

Good luck,

Kevin.

[CastleMGBV8]

Dave,

I am assuming the shell already has the forward radiator position mod which is the only difference between an early and late rubber bumper shell.

Kevin.

[tetlow]

Hi Kevin

Thanks for the help.

I have bought a LT 77 conversion kit from the MGOC so it should be OK. Don't ask how much is was.

Perry has given me a shed load of info and as today will be the only day without rain for the next few months I had a go with the cutting disc

I have fitted the crossmember and need only to drill 1 hole each side, but due to not being able to lower the engine due to the power steering cylinder, the box does not sit parallel with the road.

My main worry now is how much clearence to I need for the top of the box. I have 1/4" at the moment.

Regards
Dave

[davemgb]

I've never fitted a steady bar to my BV8 but then I've always used genuine BV8 or RV8 engine mounts and never had a problem. Cue string of engine mount failures....

Perhaps I should drive it harder http://stevekilvington.fotopic.net/p45107262.html

How far above the crossmenber is the sump? I assume you have the RB spec crossmenber with its integral spacers - its difficult to get a clear picture from the web of how much bigger the power steering rack is than the standard one.

You could take the power steering off

Dave

[tetlow]

Nice Pic.

Were you in the lead or holding them up

The sump is about 1" above the cross member I think!! it is a MGOC modified Rubber Bumper one for the power steering. The steering is nice. Thge lock is poor but I can park it with my pinky.

I will cut as much off the tunnel as I can but if the box was meant to be higher then the box crossmember / cotton reel mounts must be wrong.

I can imagine the engine twisting a bit but will it go up and down??

I will just have to keep the 140+ for the track.

Dave

[mgbv8]

Dave
There are only two fixings each side on the chassis rails for the Xmember to bolt onto. And they are not captive nuts. It is a threaded plate that is held in place by lugs inside the chassis rail. If you wiggle one bolt you will see that the other bolt moves with it when loose.

[mgbv8]

The standard engine mounts are fine for most use. But mine do tend to twist too much and the scoop fouls the hole in the bonnet so I have a beefy staedy bar on mine. For engines that dont stick out through the bonnet the normal mounts are fine.

[davemgb]

Nice Pic.

Were you in the lead or holding them up

Dave

It was qualifying so leading isn't really appropriate, but I did out qualify them

Dave

[JC.]

The trans mounts I got from davel vale didnt line up at all with my cross member. I am using Clive wheatley alloy mounts though? maybe thats why.
I had to notch the rear of my trans tunnel so the gear lever would select all gears.

It'd proberbly be better to weld the tunnel. Its a fairly solid looking thing at the front where the step is.