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Kmc

Series 2 v8 gearbox question

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Hi,

New to the forum. 

I am after some advice on fitting a Rover V8 with a Lt77 into a series 2a SWB.

i have purchased a second hand 2.5 Defender gearbox to mate up to Philips adapter and then onto the engine however the flywheel clutch bolts are too close to enable the gearbox to bolt on. 

The flywheel bolts are very close to the adapter ring and will not allow the LT77 to bolt on. 

Am I using the wrong set up? 

Any advice would be greatly appreciated.

 

9E42E13B-196B-44DA-8E12-7CF23BA8E442.jpeg

D7CCF9DB-993D-4BEC-ABE8-B866E580E593.jpeg

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Welcome!

I'm not familiar with specific adapter plates but it looks like that one might be designed for a smaller / thinner flywheel, such as the Rover SD1 type. However, that leads to a custom clutch release bearing and a loss of low-down torque which isn't so great.

Any reason you're using a 4cyl box & adapter rather than a V8 box that will bolt straight up?

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Thanks for the response Fridgefreezer. 

I thought I had to use an adapter plate to use the defender Lt77 great box with its short bellhousing. It may have been designed for the original series gear box. 

Do I need to ditch the adapter plate and use a specific v8 bellhousing? 

Discovered that the discovery LT77 has a longer input shaft which would lead the gear selector to come up in the seat box. 

I would like to keep the gear lever in its original position. 

Have to to say the gearbox for the conversation has been a bit of a minefield. 

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I think your best bet is to get a V8 and LT77 from an early Defender, 90 or 110.  That way, everything is guaranteed to fit without alignment or stree issues.

This adaptor plate is clearly for a different flywheel and clutch.  You’d have to test fit it to the bell housings to see which kind of gear box it’s meant for, but it looks like short stick LT77  (Discovery) to me because of the stud pattern.

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I've the same adapter housing, the flywheel looks very different.

I'll see if I can get some pictures this evening.

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V8 Defenders had various gearboxes but you can either get a genuine LT77 with V8 bellhousing, or far more common (easy to find) would be the LT77 or R380 from a Disco or RR with a kit from Ashcrofts to fit the Defender shifter housing and put the gearstick in the right place. Or get Ashcrofts etc. to build you a box to spec.

The only issue is length - in an 88 the 5-speed + LT230 combo is very long and leads to a very short rear prop, unless you push the engine forwards.

May be teaching you to suck eggs but the different variants for different engines had different bellhousings & input shaft lengths so it's not just swapping bellhousings around, you need the right box.

Here's my V8 + R380 + LT320 in a 109:

2006-09-05-00h42m38.jpg

 

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There is a short bellhousing LT77, isn't there? One of the 4 cylinders? Maybe this is the reason for the adaptor: The V8 bellhousings tend to be loooooooooooooong.

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2 hours ago, lo-fi said:

There is a short bellhousing LT77, isn't there? One of the 4 cylinders? Maybe this is the reason for the adaptor: The V8 bellhousings tend to be loooooooooooooong.

Yes but they're rare as rocking horse poo, although Keith Gott might've had some. That still leaves you with an adapter plate to the V8 and potentially oddly positioned engine or gearbox, at least with stock V8 bits you can use stock V8 clutch, exhaust down-pipes to Y piece & mounting on the transfer box mount, etc.

The V8 bellhousings are ~30cm long (ISTR LT77 is ~310mm, R380 is ~285mm) which gives the same overall length of gearbox + bellhousing for each.

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Interesting... Having seen worked on a 200tdi with some flavour of LT77+LT230 badly shoehorned into an 88, I'd be trying to save every cm I could scrounge. Had to take the transfer box off to get at the handbrake drum :ph34r: I'm not sure if the V8 is any shorter.

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A proper serpentine V8 is usefully shorter (and simpler), and you can gain quite a lot of space at the front by trimming the rad panel.

My V8 is set a fair way back but there's space a plenty should you need it:

engine_space.jpg

With the rad & fans in place there's still tonnes of space:

IMG_4163.JPG

 

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Posted (edited)
11 hours ago, Snagger said:

I think your best bet is to get a V8 and LT77 from an early Defender, 90 or 110.  That way, everything is guaranteed to fit without alignment or stree issues.

This adaptor plate is clearly for a different flywheel and clutch.  You’d have to test fit it to the bell housings to see which kind of gear box it’s meant for, but it looks like short stick LT77  (Discovery) to me because of the stud pattern.

Hi Snagger,

i bought a second hand Series 1 Disco for the engine which was a manual 3.9. I read that you could not use it’s LT77 as the remote comes up in the seat box as this is towards the rear of the gearbox. This is why I then bought a second hand defender gearbox as the remote is forwards and they have a shorter input shaft.  I have still got the Discovery LT 77 but threw away the bellhousing as it looked to be too long. 

These are the pictures of the defender gearbox with the remote being forward. 

AE7781F3-52BB-4ACD-BBC7-2B5D1102F239.jpeg

B7DBF505-DDB9-42B8-88F7-E4FB778995D2.jpeg

Edited by Kmc

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8 hours ago, FridgeFreezer said:

V8 Defenders had various gearboxes but you can either get a genuine LT77 with V8 bellhousing, or far more common (easy to find) would be the LT77 or R380 from a Disco or RR with a kit from Ashcrofts to fit the Defender shifter housing and put the gearstick in the right place. Or get Ashcrofts etc. to build you a box to spec.

The only issue is length - in an 88 the 5-speed + LT230 combo is very long and leads to a very short rear prop, unless you push the engine forwards.

May be teaching you to suck eggs but the different variants for different engines had different bellhousings & input shaft lengths so it's not just swapping bellhousings around, you need the right box.

Here's my V8 + R380 + LT320 in a 109:

2006-09-05-00h42m38.jpg

 

There seems to be various types of bellhousings for the v8. The Range Rover and Disco seem to have a longer one due to the input shaft and with what looks like ribs or strengthening on the case. Yours looks like what I had fitted in my MGB which came off an SD1 and Lt77. 

Can I just fit one of the SD1 or are the defender ones different to the RR and disco.? 

As you can see I am somewhat confused and no your not teaching me to suck eggs. 😂

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7 hours ago, lo-fi said:

There is a short bellhousing LT77, isn't there? One of the 4 cylinders? Maybe this is the reason for the adaptor: The V8 bellhousings tend to be loooooooooooooong.

That’s why I thought I needed the adapter between the 4 cylinder defender gearbox and bellhousing. Sadly it fouls on the cluch and you can’t bolt it up. 

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Posted (edited)

Thank you all for the advice so far.

I have looked on eBay to get an idea of some of the bellhousing and gearbox options. 

SD1 

P38 

Not sure if these would fit as I want to keep the gearstick in the original position. 

The vehicle is just a chassis at the moment so can move the engine to suit but will want to keep the Series Front end. 

 

AC8882FE-5214-4B6D-B8A8-AAB703E5F759.png

3E33D474-B808-4DE6-820B-F88EC81B535B.png

Edited by Kmc

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You need the normal LT77 V8 bellhousing as fitted to Disco 1, RRC and some early 90/110/Defender. The same one you threw away I’m afraid! Yes it’s longer but the engine sits 6” further forward in a V8 than in the earlier 4-cylinder models. It might be the same as the SD1 bellhousing but I wouldn’t know for sure. You would need to use this bellhousing with your Disco V8 LT77, using the Ashcroft adaptor kit to bolt your Defender shifter assembly on top. This effectively gives you a “Defender spec” V8 LT77.

With that bellhousing the engine will drop straight onto standard V8 mounts and the gearbox will sit onto either V8 mounts bolted to the chassis or alternatively a 300Tdi crossmember - though the latter may clash with a V8 exhaust system. That way standard V8/300Tdi/Td5 propshafts will fit and the R380 seatbox, tunnel and floor plates also.

Anything else will mean custom something, which isn’t a bad thing if you can make it up but it’s certainly easier when everything is as per the factory as far as possible. Appreciate parts are rather harder to come by over there though. 

Ive presumed that you’d be converting to a Defender tunnel and seatbox as this would make fitting easier.  If you want to keep the series seatbox then you will likely need to keep the gearbox in the early 4-cyl position and have custom engine mounts. 

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58 minutes ago, Kmc said:

That’s why I thought I needed the adapter between the 4 cylinder defender gearbox and bellhousing. Sadly it fouls on the cluch and you can’t bolt it up. 

I think Fridge is right, the only major problem there is that you've got the Land Rover flywheel with an adaptor made for the Rover car one, which is thinner. Sourcing an SD1/P6 flywheel will probably make it all work with the bits you've got. I believe I've got one, so if you don't mind a trip up to Basingstoke to my lock up, you're very welcome to compare. 

As others have commented, you'll lose a little low down grunt with the lighter flywheel, but having driven both I'd say it's not the end of the world. 

My 109 V8 build thread for reference:

I believe the LT85 is a little longer than the V8 LT77, but not by much. Again, you're more than welcome to poke about the 109 to get a feel for how it all fits with the long V8 bellhousing.

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Thanks for the response retroanaconda.

I will have a look out for a bellhousing and see what I can source. Gutted I threw it out now but at least I kept the gearbox and transfer box.

 

what is the difference in the seat boxes between the series and defender models?

 

 

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Not a lot of difference between seatboxes, I have a TD5 box in my 109, had to notch the battery tray side to clear the chassis. You will have to modify the box & tunnel & bulkhead whatever you do, a Defender seat box won't really help much.

The p38 gearbox will be all sorts of wrong - odd concentric clutch release, different clutch, different transfer box which nothing else fits (see the odd back end on your picture? That only mates to a P38 transfer box).

This is the Disco to Defender shifter adapter: https://www.ashcroft-transmissions.co.uk/diy-rebuild-kits/r380-rebuild-kits/selector-rail-adapter-yolk.html

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I'd say, your choice of parts is spot on, as mentioned before, the length of an original V8 gearbox is not going to work with your wheel base. Did you try to fit cap head bolts? I think the clutch cover would still foul though.

I think with this adaptor, you are meant to redrill the flywheel to take a series 3 clutch, which is smaller and would also solve your problem.

If all else fails, just swap the flywheel, or get it machined thinner, the least you can get away with.

edit: just saw this on our very own forum:

Daaa

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My 1st conversion was a 3.9 with SD1 flywheel and it was a bit too easy to stall, especially off-road, compared to a regular V8 - hard to describe but the stall point was not where you expected it to be given how torquey the engine was.

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you can use this flywheel, adapter ring and LT77 bell housing but you have to redrill the flywheel and fit the 9.5" diameter clutch from the 4 cyl

Dave

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Thank you all for the info. I will keep an eye out for a second hand bellhousing and keep you updated. I am sure I will be back with more questions as I get the build underway😂

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I think John has some of the widest V8 experience on here.   f anyone can work out how to get that engine and gearbox in, especially behind a standard front end, I think it'll be him.

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16 hours ago, Kmc said:

Thank you all for the info. I will keep an eye out for a second hand bellhousing and keep you updated. I am sure I will be back with more questions as I get the build underway😂

Martin at www.rrpartsltd.co.uk will have one.

@Snagger  OK what are you after eh? :ph34r:

  • Haha 1

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