Thread: LT77 and LT85 dimensions differences

AFAIK the bolt positions on the chassis didn't change between either of those boxes. The RH mount bolts to the LT230 transfer case and as the chassis holes on the LH side are fixed then the appropriate bracket that bolts to the particular gearbox should compensate for differences in the gearbox.

When converting to Tdi, I took an LT85 out of my 130 and fitted a LT77. The mounts were fine, but the prop-shafts wouldn't fit and I need new ones. The front was too short and the rear was too long IIRC. I used the front prop off the donor vehicle, but had to buy a new rear on as the donor was a 110.

I have got a LT 77 out of a disco fairly sure there weren't any differences. Also have a couple of LT85's, I would have to measure them though. As far as I know any differences were taken out in the bell housing and the LT230 that is on both are in the same spot etc. If you are thinking of pulling out an LT85 and putting in an LT77 that is a big backwards step in strength! I have had both apart, the 77 is a nicer box especially to drive but they are a car gbox compared to an 85.
Tim

Thanks Tim

The issue is that I have a V8 D150 with the LT77 and I'm going to fit a 4BD1 with an LT85 and want to sort out what I'm up for.

Currently I have:

• V8 Defender LT77 and LT230
• V8 Disco 1 R380 and LT230
• LT85 Isuzu bellhousing
• County LT230 without linkages.
• Option to buy = V8 County LT85
• Option to swap = 1.003:1 LT230 for any of the above.

What I don't know is:

1. if I can fit the either of the V8 LT230s to the county LT85 (linkages),
2. whether the prop shafts will be correct lengths, or
3. what transfer ratios I need for the 4BD1 (I'm thinking the 1.222:1 Disco ratios).

Diana

AFAIK all LT230s will bolt to any R380/LT77(S)/LT85/ZF (with spud shaft).

I have a (~'99) disco 1.21:1 "Q" case bolted to my LT85 at the moment. A disco case fits a defender fine, except that high and low are reversed on the shifter.

You will need a turbo with your setup. What ratio are the diffs?

Originally Posted by isuzurover

AFAIK all LT230s will bolt to any R380/LT77(S)/LT85/ZF (with spud shaft).

I have a (~'99) disco 1.21:1 "Q" case bolted to my LT85 at the moment. A disco case fits a defender fine, except that high and low are reversed on the shifter.

You will need a turbo with your setup. What ratio are the diffs?

Ben

Nothing could be slower or more thirsty than a 3.5 carby V8!

My concerns were whether the change linkages etc will fit.

I am assuming the diffs are 3.54:1 same as the rest of the Defenders.

The plan is to build the D150 with a NA 4BD1 in the short term and get it rego'ed then build up a second 4BD1 (which I have) as a turbo engine with the oil squirters, new rings/bearings etc. Then swap over the engines.

Sounds like an O.K. plan or would you go a different path?

Diana

Originally Posted by Lotz-A-Landies

Ben

Nothing could be slower or more thirsty than a 3.5 carby V8!

My concerns were whether the change linkages etc will fit.

I am assuming the diffs are 3.54:1 same as the rest of the Defenders.

The plan is to build the D150 with a NA 4BD1 in the short term and get it rego'ed then build up a second 4BD1 (which I have) as a turbo engine with the oil squirters, new rings/bearings etc. Then swap over the engines.

Sounds like an O.K. plan or would you go a different path?

Diana

The perentie 6x6 runs 4.7 diffs, 1.1(or 1.2?) t-case AND a turbo.

I would suggest you don't try a 1.003 t-case and NA engine. You may even want to go to a 1.4 t-case with 3.54s. (probably the best option - especially if NA).

Many of us have shown that the NA engine holds up fine with a turbo and no oil squirters. I would turbo from the start, then you don't have to change t-case ratios after fitting a turbo.

Thanks Ben

I will do a diff ratio calculation on Friday.

The turbo build up would be easier during the vehicle build up, no doubt about that, but was wondering about the 15% increase in engine size. But checking the NSW Transport Roads and Maritime site today. I find two things:

1. A GVM of 4700Kg takes the D150 out of the light vehicle mods.
2. The 15% rule has been replaced with a calculation based upon tare weight, allowing something like a 9litre engine. (Who would have thought the ex-RTA could be logical?)

Diana