Clutch covers - SD1 V8 vs. LR 4 cylinder

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Quagmire
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Clutch covers - SD1 V8 vs. LR 4 cylinder

Post by Quagmire »

This might seem like a bit of an odd question but does anyone know if there are differences in the clutch covers used on 4 cylinder LR's with LT77 boxes, vs the ones fitted to SD1 v8?

Reason i ask is that I am planning on converting my Rover P6 to LT77 in place of the 4 speed it currently has. A morning of internetting has me believing the following to be true:
  • I believe that the LR V8 clutches are 10.5"/267mm diameter, whilst the 4 cylinder ones are 9.5"/241mm. 

    The Rover SD1 uses a 9.5"clutch - same as the 4 cylinder LR's. 

    Leaving out the 10 spline versions both SD1 and LR friction plates are 23 spline.

    SD1 clutches are £££ compared to LR parts.
From googling it appears that you can't fit the normal, larger LR V8 clutch because the clutch cover fouls the shorter SD1 bellhousing. 

So, what are the dimensional differences between the LR 4 cylinder cover and the SD1 V8 version, and why can't i use the cheaper LR parts?

Many thanks


1974 Rover 3500s
1984 3.5 90
1959 2.25 series 2

garrycol
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Post by garrycol »

I cannot answer your question re clutch friction plate sizes but why would you go to an LT77 gearbox over the R380 that replaced it. As a general statement an R380 will go where an Lt77 will go and you don't have that awful reverse up next to first issue with the R380. I had a Lt77 Disco for a while and went into reverse a few times instead of first and soon changed over to an R380 Disco - much much much nicer.

When you talk about 4 cylinder landrovers in front of the LT77 what 4 cylinder are you talking about? The 2.0 litre petrol or the 2.5 litre diesel? The diesels certainly had a shorter bellhousing but I am not sure if that impacted the clutch size. Also note the above if when you get your LT77 or R380 gearbox - those out of a diesel may have a shorter input shaft (and bell housing) - so just check before you buy.

Garry

Quagmire
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Post by Quagmire »

To answer your first question - I have a complete SD1 LT77 on the floor of my garage and have done for quite some time, it would be a shame not to use it.

The LT77 in my V8 90 is lovely - although that's because I rebuilt it! :D

I have never driven an R380 so can't comment on the difference though... I could indeed be missing a trick by going with the LT77, but I guess what you don't know can't harm you!

By four cylinder engines I mean just that, all the four cylinder engines (Excluding the spurious Italian MPi powered Defenders)that were fitted to the 90/110/Defender, whether it be petrol or diesel - as far as I am aware the clutch setup on them all is the same. Off the top of my head that would be:

Petrol:
2.25/2.3
2.5

Diesel
2.5 NA
2.5 Turbo
200 Tdi
300 Tdi

My 90 had the 2.25/2.3 Petrol fitted when I bought it many moons ago, the bellhousing on that box was very short like the diesel. Probably shorter than the SD1 unit in fact.

Basically i am relying on the fact that LR/BL never re-engineered anything unless they had to. With the fact that the 4 cylinder LR clutches are the same diameter as the SD1 unit and both go on the end of an LT77 I am hoping that everything else is the same too!
1974 Rover 3500s
1984 3.5 90
1959 2.25 series 2

DaveEFI
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Post by DaveEFI »

It's one thing makers giving different part numbers to the same item which they don't make themselves, but can't see this happening if you buy from the clutch maker direct. So the price would be the same from them if the item is.
Dave
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garrycol
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Post by garrycol »

Looks like toy are across the issues (except for the clutch size) - the R380 is a nicer box than the LT77 but if I had an LT77 sitting on the floor I would use it too.

Just looking at one supplier here http://www.rovahfarm.com/defenderclutch.htm would seem that you are correct in assuming the diesels had the smaller clutch.

garry

ratwing
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Post by ratwing »

FWIW this is what I've gleaned from internet searches, I kept these details to give it a go if/when my clutch needs replacing.

I haven't done it myself yet so can't definately say it'll work.

STC8358 clutch kit for 200tdi LandRover - the cover:
- fits SD1/p6b flywheels
- is dimensionally similar
- has 15 spring fingers whereas the SD1 has 19 although they are the same thickness;
- the centre plate:
- again, dimensionally similar
- fits the LT77 splines
- has different springs between the splined centre and friction plate.

The release bearing in the kit is different so needs the matching arm/pivot ball/slipper pads/clip which might mean a different length clutch slave pushrod.

Quagmire
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Post by Quagmire »

Great info - thanks!
1974 Rover 3500s
1984 3.5 90
1959 2.25 series 2

unstable load
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Post by unstable load »

I would think the Landy pressure plate would possibly be fitted with stronger pressure springs due to the weight of the vehicle, and possibly different friction material, but I can't see any reason why the clutch can't be used in a lighter vehicle.

I used the SD1 pressure plate on my P6 conversion and later, when I had finally comprehensively killed the LT77 and fitted the Jag box, all I did was swap clutch plates and use the SD pressure plate again.
Cheers,
John

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