Thread: 101 V8 bellhousings to R380

Hi Diana

I've been investigating putting an R380 into my 101 for a while but have put the idea on the back burner after your roverdrive information. If you also factor in the winch pto drive on the 101 there is quite a bit of work in making the R380 fit. I thought the way forward with the bellhousing would be to use one from the 2wd applications of the R380 or LT77. The bellhousing for both is the same but the pinion must be from the MGB RV8 which I think is the only 2wd R380 application ( could be wrong? ). I looked at this for the 101 and it gets the propshaft drive flanges close to their original positions with the LT95. However I was recently told the 2wd bellhousing wont accomodate the larger clutch used on 4wd vehicles but I haven't checked this out yet.
Hope this helps
Dave

I have somewhere in the back of my mind that the bellhousing and input shaft for a R380/300TDi Defender is shorter than a the V8 version in the Disco. Am I right or wrong?? If correct is this any use??

Garry

Originally Posted by garrycol

I have somewhere in the back of my mind that the bellhousing and input shaft for a R380/300TDi Defender is shorter than a the V8 version in the Disco. Am I right or wrong?? If correct is this any use??

Garry

The LT77/S in the defender had a short bellhousing, and I believe some interim models had the same bellhousing with R380.

Ashcroft have recently started selling the latter (R380 short bellhousing)
Ashcroft Transmissions

The downside is they only come in a Tdi/5 bolt pattern.



As the V8 has a smaller spigot diameter, I can't imagine it would be too hard to buy one of these, machine the input shaft down, and machine the engine side of the bellhousing down and weld a new ring on which mates to a V8.

The 101 I drove with the R380 gearbox and later transfer case used standard bell housing and the the gear box mounts were moved rearwards to make the thing fit.
How the the standard R380 stuff could fit with the steep tailshaft angles was because the chassis was lenghten to 130 inches.......search for the thread in this section of aulro.
Why would you want to go to a weaker and less reliable R380 gearbox when the the LT90 works so well ?
I have just arrived home from Holidays pulling 1.5 tonne of trailer cruising at 100 kph at 2800 rpm with stock 3.5 litre v8 on gas using stock gearbag.
transfercase ratios,diff ratios and overdrives can all be changed on a 101 to get what you want and there has been much discussion about this in previous threads..
Garrycol has recently fitted the fairly overdrive to his 101 and it would be interesting to hear his thoughts.
use the fairly overdrive only in top gear and it should last a long time.
I could be wrong....but I though a R380 is a straight 5 speed box and not overdrive in 5th any how and shouldnt make any difference.
Interestingly my 101 starts off from standstill n 2nd gear with light loads with first only used for hill starts . off road work and getting heavy trailer moving from rest.

The Fairy overdrive works as advertised - on the highway engine speed is reduced - I do not have a tacho to check by how much - fuel consumption on gas is improved by 10% and the truck is a little quieter (I do not have the O/d whine most complain about) though it is tyres and noise from the exhaust pipe that is unchanged. Top speed is unchanged (113-115kph) and struggles to get there with O/d.

With O/d in the 101 is a bit of a slug and as expected is slow to accelerate and dies pretty quick - however on mine I find 3rd gear much more usable with O/d on than when it is out - 3rd normal is a bit low when going up hill where 3rd (O/d) is just right.

Overall I do not like using O/d unless cruising on open flat highways - the 101 is just so much sweeter to drive with no O/d. I guess it is that the torque of the 3.5 is just a little shy of what is needed to run higher gearing. But then as said - the O/d works well for what it is supposed to do. I think with high speed gears and O/d it may be a bit much for a 3.5 in all but ideal conditions - downhill with a tail wind - certainly going into wind would be a problem.

PeterP is putting in both into his 101 so I will be interested to see how it goes - though he has a new engine and is hi compression. I have a 3.9 to rebuild one day and am looking at options for this project if it ever happens so watching this thread with interest. As I have a good spare LT95 out of a Stage 1 was contemplating using the gearbox as spare parts for my 101 and cutting off the tfr case and connecting it to a R380 and a short bellhousing on the back of my 3.9 and putting that in the 101. Short Gearbox/tfr length is important in a 101 (same as a RRC with a 5" lift). I think it would easily pull higher gearing using combinations of R380 5 speed, different tfr case gears and even the Fairy O/d.

Any one tell me the length of an R380 gearbox housing and how far the output shafts and input shafts stick out of the gearbox.

Cheers

Garry

Originally Posted by 101 Ron

Why would you want to go to a weaker and less reliable R380 gearbox when the the LT90 works so well ?



I could be wrong....but I though a R380 is a straight 5 speed box and not overdrive in 5th any how and shouldnt make any difference.

I didn't think Diana was talking about fitting it to a 101 necessarily???

You are wrong. 5th is 0.77:1 in diesel boxes and 0.73:1 in V8 boxes.

The R380 seems to hold up behind a 4BD1T (including in 120s and 130's). I can't see why it wouldn't hold up in a 101.

Diana is looking to fit a ex disco V8 and R380 into a 109 F/C and I can see no problem with that other than finding room for the motor under the cabin.
The longer chassis and different layout should help lenght wise.
Dave jump is looking to fit the R380 to a 101 and is a different machine with its own problems.
I own a defender with a 300 TDI and a R380 and I know witch gearbag lasts longer and doesnt drop brass at every oil drain or wears the splines and front main shaft bearing.
I also have had a lot of time with a Stage one V8 series three table top with LT95 and it never had any gearbox or transfercase weaknesses.

Originally Posted by 101 Ron

I know witch gearbag lasts longer and doesnt drop brass at every oil drain or wears the splines and front main shaft bearing.

No arguments here. However if and when I acquire an FC, it will be getting an isuzu engine and isuzu 6-speed...