v8 series with lt77 gearbox?

hi, i have a v8 series 3 land rover with its original gearbox...i want to fit a lt77 gearbox without transfer box making it rear wheel drive only...does anyone have any advise on which is the best way to go about this?i know i am going to be asked why?? i do not do off roading and have never needed to use 4wd . i am looking for a smoother ride in my truck on the road and i am planning a long European trip and want a reliable gearbox.thanks

I think you will find the issue is the reason for the transfer box. As a straight prop to the rear will put a heavy stress on either prop or diff gears. I guess being the series 111 just remove the front drive shaft to get the feel of rear drive only.

Maybe not a Land Rover and not a Series III?

I would agree with @300bhp/ton! If you want a smooth ride you really do not want a series 3. To get the same result you could fit free wheeling hubs or just remove the front prop. But I would have thought you are likely to very quickly destroy the axle if you run straight through with a v8. The original gearbox and transfer of set up is not inherently unreliable. And you may be better investing in rebuilding what you have rather than trying to modify and change to something differant.

hello, thanks for your replies, i have a Salisbury Rear Axle...i already have free wheeling hubs fitted and over drive fitted! but still would like to a smoother gearbox than my current one with less movement through the drive train....the engine is only a 3.5efi . i could get a custom heavy duty prop made and fit a hydraulic handbrake.i have checked the angle of the where the prop should come down and it does appear it will clear the chassis as i would not been keen on cutting the galvanised chassis!

coverworks08 said:

hello, thanks for your replies, i have a Salisbury Rear Axle...i already have free wheeling hubs fitted and over drive fitted! but still would like to a smoother gearbox than my current one with less movement through the drive train....the engine is only a 3.5efi . i could get a custom heavy duty prop made and fit a hydraulic handbrake.i have checked the angle of the where the prop should come down and it does appear it will clear the chassis as i would not been keen on cutting the galvanised chassis!

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i would get the original box done up, you can fit a lt77 and lt230 with a rear wheel drive kit in the center diff,fitting a 3.54 diff would give extra strength, ive just done that but its been an unfulfilling job as its a bodge rather than an improvement

The transfer box gives higher out put ratio than straight gearbox drive so engine would have to run higher revs for same speed.

thanks for all the input...it seems i may be looking for problems and better to leave it as it is! ....i will work with what i have....cheers

Hydraulic hand brake!!!

I have a SWB S3 with a Rover V8 (with carbs) and looked at a LT77/R380 box as when I bought it 3rd gear would make funny noises so it was either rebuild or replace. The quote for the 5 speed box was over £4k so I had the original rebuilt (and new clutch) for under £1k. Its got 3.54 diffs, FWH's and overdrive and the gearbox isn't bad, just don't give it too much welly unless in 4th, Its the steering that bothers me more.

I agree, my LWB with the Perkins 4203 and 3.54 diffs will get up to 65+ loaded but having done it once I would say never again, the steering is so light and you have to look so far ahead in case of needing to brake that its not worth the stress.

Well I’ve GPS clocked mine at 89mph (on a private road). But I do have PAS.

FFG said:

I have a SWB S3 with a Rover V8 (with carbs) and looked at a LT77/R380 box as when I bought it 3rd gear would make funny noises so it was either rebuild or replace. The quote for the 5 speed box was over £4k so I had the original rebuilt (and new clutch) for under £1k. Its got 3.54 diffs, FWH's and overdrive and the gearbox isn't bad, just don't give it too much welly unless in 4th, Its the steering that bothers me more.

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3.54 diffs? Are they out of a RRC? Only asking as I'm not sure what ratio standard s3 diffs are, and I'm about to embark on the journey of getting mine back on the road with a v8 conversion.
The v8 is out of my rrc, and I still have the axles, so could take diffs out and swap them into the series...how higher geared do they make it compared? Thanks

Gottschalk said:

3.54 diffs? Are they out of a RRC? Only asking as I'm not sure what ratio standard s3 diffs are, and I'm about to embark on the journey of getting mine back on the road with a v8 conversion.
The v8 is out of my rrc, and I still have the axles, so could take diffs out and swap them into the series...how higher geared do they make it compared? Thanks

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series lrs are 4.7 diffs ,rrc ,disco and defender are 3.54

jamesmartin said:

series lrs are 4.7 diffs ,rrc ,disco and defender are 3.54

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Thanks James

My speedo reads low, around 30 on the speedo and I'm doing over 40. Just get a sat nav to record actual speed and put some markers around the speedo to record 30,40,50,60 and 70 if brave.

I also run 3.54 and rely on sat nav and mental arithmetic for accurate speed, as some of you will know I got it wrong one day and spent £95 on a "speed awareness course" for 33 in a 30. I'm sure the irony of a speeding ticket in a Series is not lost. I like the 3.54 diffs as I'm 98% on road driving and with O/D and 235/85 is is 30mph / 1000 rpm (the Ashcroft gear calulator is very handy) but as I've posted elsewhere on the issue, reverse is ridiiculously high, even in low range. Its imposible to reverse without slipping the clutch the whole time and a lot of manourvering and pulling away loaded is done in low range.

rob1miles said:

I agree, my LWB with the Perkins 4203 and 3.54 diffs will get up to 65+ loaded but having done it once I would say never again, the steering is so light and you have to look so far ahead in case of needing to brake that its not worth the stress.

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That's a scary speed for a lot of classic landy. Like trying to stop a supertanker!

i ended up doing the conversion and its well worth it !!