A few questions for the gurus....seeing as the R380 is an updated LT77...
1. Will the LT77 rear cover fit the R380 and still have the pump etc functional?
2. Is the output shaft interchangeable from LT to R series boxes?
I have an ex-Discovery 2 R380 that ate the input pinion and I'm thinking of rebuilding it to 2 wheel drive spec for my P6, but as a 4X4 box it has the extended output shaft and no 5th gear/rear cover and I stand almost zero chance of finding 2 wheel drive R380 parts in South Africa, but there may still be some LT77s lying around, hence the questions around swapping bits across.
A few questions for the gurus....seeing as the R380 is an updated LT77...
1. Will the LT77 rear cover fit the R380 and still have the pump etc functional?
2. Is the output shaft interchangeable from LT to R series boxes?
I have an ex-Discovery 2 R380 that ate the input pinion and I'm thinking of rebuilding it to 2 wheel drive spec for my P6, but as a 4X4 box it has the extended output shaft and no 5th gear/rear cover and I stand almost zero chance of finding 2 wheel drive R380 parts in South Africa, but there may still be some LT77s lying around, hence the questions around swapping bits across.
I only have experience of the 2WD version of the box and I think they differ in that area but I'd say you'd struggle to mix and match. On the 2WD the rear case is significantly different, a fair bit larger. I think this is due to the reverse gears being sited in that casing on the R380 IIRC this is located in the main box on the LT. Arguably with a bit of ingenuity anything is possible but you need to be careful not to end up with no reverse!
Re: LT77/R380 interchangeability..
Posted: Wed Aug 16, 2023 6:18 pm
by ChrisJC
I would think it highly unlikely TBH.
5th gear is different, and that's the bit at the rear of the gearbox.
Might be worth studying a few photos on eBay to see if there are some obvious differences.
I only have experience of the 2WD version of the box and I think they differ in that area but I'd say you'd struggle to mix and match. On the 2WD the rear case is significantly different, a fair bit larger. I think this is due to the reverse gears being sited in that casing on the R380 IIRC this is located in the main box on the LT. Arguably with a bit of ingenuity anything is possible but you need to be careful not to end up with no reverse!
Both LT77 and R380 have 5th and reverse in the rear casing, that I know from having seen both models stripped down in bits.
I think my solution is going to have to be finding an R380 2WD rear housing and the correct output shaft etc and the shifter remote, or another more available type of box here in SA.
I only have experience of the 2WD version of the box and I think they differ in that area but I'd say you'd struggle to mix and match. On the 2WD the rear case is significantly different, a fair bit larger. I think this is due to the reverse gears being sited in that casing on the R380 IIRC this is located in the main box on the LT. Arguably with a bit of ingenuity anything is possible but you need to be careful not to end up with no reverse!
Both LT77 and R380 have 5th and reverse in the rear casing, that I know from having seen both models stripped down in bits.
Humm, looking at this
(
video between 3:55-5:00 shows that the R380 has reverse in the rear casing (with syncro) while the LT77 has a simple idler arrangement located in the main (cast iron) housing.
In fact you can see the reverse idler of the LT77 'box (in the front) in the graphic above, not seen in the R380 as it's in the rear casing (on the right in graphic)