Anyone run a HRTC behind a V8 or Tdi?

[Snagger]

I'm still mulling over a few ideas for my 109's transmission to get the overall gearing up a little from standard SIII with overdrive, including upping the diffs, as it's just too noisy on long drives, but I'm worried about over-stressing the gear box.

The 3.54 diffs broke the gear box and were too tall anyway, but 4.1s would be a very simple conversion compared to ripping out the whole transmission and modifying the chassis and cab to suit. So, the question is, has anyone run an Ashcroft High Ratio Transfer Case behind a much driven Tdi or V8 for some time, and how well did the box cope? I think this would have a slightly greater strain on the box than upping the diffs to 4.1, as long as the overdrive was only used in 4th, so I'd love to hear how well SIIIs with HRTCs have stood up in the long term.

It looks like my hopes to fit a ZF auto are out - it's just too long. So, it comes down to a manual transmission. Given that, I'm wondering how worthwhile all the effort in fitting an LT77 and LT230 or BW unit is, if I can do something easier without breaking stuff.

I still fancy the idea of an LT77S and BW, but it's a hell of a lot of work and cost, and would leave me with a few issues to sort inside the car. Diffs could be an easier solution, if the box will take it, but I'm worried after breaking the box a few months ago. I'm also becoming increasingly wary of complex mods, like swapping the whole transmission, because they all seem to have serious consequences, sometimes unseen, especially where mods interact with each other.

[Gremlin]

I have first hand experiance with your last sentence.........................some are still unsorted, needing mods to solve my previous mods. I have learnt to live with them.

As to choice i cannot help, but i have been in your shoes several years ago. I have ended with the lt77/lt230, i have been happy with it, although i wish i could go to an auto.

G

[Snagger]

I would guess that the auto is about the same length as a short stick LT77 or standard R380. So, it would fit if you were willing to cut out all the cross members, including the one under the rad and move it forwards. I have the Stage 1/Defender body already, so that would be doable, but I don't want to chop up a galv chassis.

I'd still like to look at your 109, Grem, when I come down there! An LT77S and BW might till be viable, and I could do with the inspiration and your lessons!

[Gremlin]

Sure no problem, i already chopped or moved most of the x members so in my case an auto would just involve propshafts and gearbox mounts, As my engine has no room to move forward, so that has to stay put. I belive an auto is 4 inches longer then what i have now.

Now that i think about it i might have issues with my front prop clearing my last x member relocation...........errr forget it, another mod fixing my previous mod...........

Let me know when you fly here..........

G

[Snagger]

4" is the number I was told by my local specialist. I was just wary because 4" is also the length difference between a stock Series transmission and a short LT77 mated to a Series transfer box with the Ashcorft adapter.

Anyone know how much lower or more offset the transfer box outpu shafts are on the later units than the Series'?

[Gremlin]

Found these for you..................

Front of bellhousing to rear output flange:
TF727 and LT230 - 36.5”
ZF auto and LT230 - 38"
LT77(200tdi) and LT230 - 31"
SIIA gear and transfer box - 28"

So basically the auto will be 10 inches longer from a series box, in my case 7 inches, assuming the above are correct. That a lot!!, so in my case i must relocate my gearbox x member and mounts plus another set of propshafts, probably making the front one longer than the rear!!!

No thank you, manual it will remain..........i thought the differences might be closer making the swap relatively simple in my case.

G

[FridgeFreezer]

Anyone know how much lower or more offset the transfer box outpu shafts are on the later units than the Series'?

If you mean the prop output offset, it's the same on all classic LR's (Pre-P38 era). I reckon you should bite the bullet and bolt a 5-speed + LT230 in, it is designed for your engine and 3.54 diffs and is so much stronger.

I'd always use a tape measure rather than asking people how long transmissions are, where sticks, mounts, or flanges are etc, as you can never be 100% sure they're looking at the same thing you think they are. Just get to a club event and crawl under a few people's vehicles with the tape measure & digital camera.

[Snagger]

Thanks lads! I agree with you, Fridge - accurate measurements done by yourself are vital in the final planning stages. At the moment though I'm just trying to consider my options. Certainly the desire for a tougher transmission than the Series is there - the prospect of a single gear box for all the main gears rather than having a separate lever for a pseudo 5th, with the mild nuisance that creates slowing down for junctions, and the prospect of a much quieter set of gears (the SIII box and the overdrive make a bit of noise, especially on over-run with enough throttle to prevent engine braking, so they chatter a little with all the back lash). And I do fancy permanent 4wd.

I think you're right, Fridge - as easy as the diff swap would be, it doesn't address the fundamental weaknesses of the existing transmission, while going with a later transmission and standard 3.54 diffs, which I already have and would thus cost nothing, should cost about the same in buying, even if it's a little more graft to fit.

Moving the engine forward 3" shouldn't be too challenging, either. A pair of engine mounts and a little fiddling with some of the plumbing would be all that's needed. It'd create a bit of space between the bulkhead and engine, too - Marsland fitted my mountings and gear box cross member well aft of where they're supposed to be, so the engine is a bit tight and more airflow would be welcome around the back of the block and head. It'd allow a noise blanket or a second layer of Dynamat or Noise Killer sound proofing on the bulkhead, too. I don't think cross members will be a problem - the diff inclination of the front axle has my front prop close to horizontal with the vehicle parked. Now that I have sorted out the engine mount, a new bracket for the chassis would be simple enough. The only present concern is the proximity of the prop to the oil filter, which may have to be relocated with a remote kit. See - mods interfering with each other again, requiring tertiary mods to resolve conflicts!

So, does any of the Series tunnel fit with the LT77, with the engine moved forward, or does the whole tunnel have to come out and bulkhead/seat base need trimming? I'd be very keen to see photos of how you two did it, given your Jedi-like abilities on modifying these buggers!

This means I'll now be looking out for good deals on a 5-speed and a 1.22 transfer box to go with it (don't want to go for a 1.44 and overdrive again - I want to keep it as simple and robust as possible). Is there much difference in robustness between an LT77S and an R380? Obviously, the former will be easier and cheaper to source in short form. Likewise the transfer boxes - is there much benefit to the LT 230Q over the BW? I know the BW goes through tyres faster and the viscous unit is expensive if it seizes, but I do like how it behaves in my RR. Is the 230 a better alternative, or just a bit cheaper to live with?

Sorry to keep asking similar questions over several threads. I like to research things thoroughly before embarking on mods to make sure I have the best solution and don't run into problems. Doesn't always work out as trouble free as I'd hoped, but I havene't had too many issues over all except this front diff position!

[FridgeFreezer]

I couldn't really tell you what a standard series tunnel comes out like - my truck was 6cyl (different bulkhead, gearbox location, etc.), at rebuild the engine & box were put quite far back and the tunnel was made up by miketomcat as he's a fibreglass guru. It looks odd here but it does save the traditional long reach for the sticks:

Engine location, front axle is in standard place, you can see the crank nose is behind the axle line:

[Snagger]

That's pretty smart - I like it. I don't have as much space as that under my bonnet, but because I mounted the Tdi rad and intercooler ahead of the front cross member and used an electric fan ( ), I do have plenty of room for the engine to move forwards.

I have a Wright Off Road matting set, which I'd like to keep. If the tunnel has to be significantly altered, I'd probably look to fit a Defender one and maybe get a new floor mat from Drew rather than replace the whole kit, but if I had to do something custom, then ali sheet with noise proofing sheeting and a little carpet might do the job, concealed as much as possible by a centre tray over the tunnel, like the Mudstuff tray. As far as stick position goes, I already have a cranked stick on my s

SIII box because the standard stick fouled the Mudstuff dash centre console with all my accessories - it made driving so much easier without that reach, so if the stick on the 5-speed ends up in a funny position, I'll have no compunction in taking to it with the vice, blow torch and scaffold tube like last time!

[FridgeFreezer]

You might find various bits of defender tunnel or modifications thereof might fit, fundamentally there's nothing major going on - a lump under the floor with a pointy stick is moving a bit forwards or backwards. The glass tunnel was a product of convenience - it was quick, guaranteed to fit, and I didn't have to whittle it from ali. It makes a HUGE difference to noise & heat in the cab too as it fits so snugly and doesn't conduct heat through.

You could make a more standard looking one by the same method, it's quite simple, although unless you're Mike and have his Jedi force-field you will end up wearing a lot of resin...

[Gremlin]

I have a long stick lt77 of a standard defender one, so that is what i can talk about. My tdi is approx in the same place as a normal series engine, give or take and inch here and there.

When i fitted mine and had the series bulkhead, i did have to modify the lower part of the bulkhead. I then used standard floors and tunnel bits for a turbo d landy, i slightly modded the part that attaches to the bulkhead. It was a rather simple job to get the 110/90 bits to fit. Ah you also need trim the seatbox, and get creative with the hand brake linkage if you keep the series system.

Pics later as i search up in the archive..................

[Gremlin]

Pics are from the last rebuild, My first installation was undocumented, but i put some pics of the old modified buklhead.

Standard items

Trimmed to fit, this was rather strange, as i have a 110 bulkhead and 110 seatbox and yet the standard tunnel did not fit, while on the other hand i recall that with the series bulkhead i had to extend the tunnel by about an inch. But i changed so many things at once that it was rather difficult to see why and what changed. (also my engine and box combo seem to be further back then they should be........)

All done

The old bulkhead

If i come accross any more i will post up

[MECCANO]

Nick, when sticking the LT77 in the Lwt, it was the High/Low and Diff lock linkages that caused clearance issues with the tunnel. If they weren't there it would be a stock profile. I also had clearance issues with the lt230and floor between the tunnel and hand brake leaver

If your using a BW transfer ( i would recommend it to reduce tramp) you wont have clearance issues with that anyway, but I found even sitting the lt230 as low as possible, the bolts for the diff lock selector housing barely cleared the floor with the box positioned 100mm forwards from the standard series position.

on the BW i believe you still have a high low selector linkage?!?, if so you might want to look at a td5 disco manual box, they use a cable as apposed to a solid bar.

[Snagger]

The BW has the forward/aft movement of the small stick to select high and low, but no lateral movement as there is no diff lock. I had no idea the Discovery II used a cable for the high/low selector - hand to know if it becomes a snag.

I hadn't considered that the BW might reduce shock loads and hence axle wrap on the front axle. That'd be beneficial too.

When you say you positioned the gear box 4" further forwards, did you put the rear output flange of the transfer box in the same place as the original transmission? That'd be handy as it'd keep the rear prop standard...

How did you guys mount the transmission - did you fabricate custom mountings to attach to the Series transmission cross member, or did you drill and sleeve the chassis to mount directly to the chassis rails?

[FridgeFreezer]

Hi/lo open/lock are only levers, the mechanism can be modified, rearranged, cable operated or even replaced with something else such as pneumatic, hydraulic, or electric operation. SimonR had some good thoughts on that stuff yonks ago using mini pneumatic cylinders filled with hydraulic oil (or brake fluid) giving a very positive & strong action.

I'm not sure I follow how the BW reduces tramp, I can see it limits f-r slip and hence shock load if you are driving with the centre diff open and lift a wheel. I have to say the BW works nicely off-road, especially behind an auto + V8, makes for a very lazy time of things, just point & squirt.

I mounted my transmission using standard RR mounts, which bolt to the chassis through sleeved holes (M10 if you were wondering). The series x-members were just in the way so they all got junked (Stage 1 V8's did away with most of them anyway) and I bolted in a standard RR x-member (the square type) with sleeved holes again, the lower bolts meeting a small bracket under the chassis - I would've liked to tuck it all up a bit more & make it flush but that would've put the engine & gearbox quite high... always a trade-off!

You can see the ~1" bracket and x-member above the oil drum, all in all it doesn't affect the breakover angle too much:

[Gremlin]

My mounts are defender items but i welded them to the chassis, with the right hand one slightly modified to lift it up.

Pic

I hope you can make out what i did. The original mount hung too low because a 110 chassis has a lower belly, so i trimmed and chopped the mounts to suit, i did not want hanging bits down. The only thing that hangs below the chassis is the whole handbrake drum assembly

Here is a rear view from underneath, sorry poor quality

G

[MECCANO]

Only because the BW will prevent all the power being able to go to one wheel, transferring enough energy for it to break traction and cause it to hop around on the leaves.

[Snagger]

I should think that the viscous coupling would have a damping effect on the torque to the front axle, reducing shock or snatch, and that should have some reduction in engine produced wrap. The reasons I want to use the BW is the fact that it works so well on tarmac roads with slippery patches as it's permanently "locked" but has the slip to prevent wind up. Its comparative quietness is a secondary benefit.

Thanks for the explanation on fitting and the photos. I'd like to keep the engine axis where it is if possible, as having the engine and transmission so low is what gives a Series vehicle such a low CoG compared to a coiler. It all depends on how deep the BW or LT230 is compared to the Series transfer box. There would be room to raise them, though, after modifying the cabin, to make sure they clear the chassis cross members - I'd rather leave the bell housing cross member in place, and the current prop angle suggests I would be able to do so with the later transmission.

Good stuff, guys.

How did you get on with the seats, Chris?

[MECCANO]

I will try and get some pics of my gearbox mounts. They bolt onto the stock series location with no mods to the chassias. i did shape the ( removable on mine) cross member under the box, but if you grind down the web under the lt230 you don't need to. A Borge and warner looks like

it would clear with no modification.

In essence, you line up the gearbox rubber with the centre line of the crossmember mounts.

Seats are still waiting on a second military roll bar, so i can securely mount the seat belts!

[MECCANO]

Found some photos of the original fab work.

I missed you previous question. No i poistioned mine based on the join between the gearbox bellhosuing and flywheel. consequently i ended up with a shorter rear prop (but used a standard 200tdi defender front prop)

Passengers side mount:

Drivers side upper:

Excuse the cat!

Drivers side lower:

[Snagger]

SO those rubbers sit on the mountings used by the Series transfer box rubbers?

[tacr2man]

I ran a heavy! 109 on the standard gearbox for years with o/d and 4.1 diffs behind a leyland 4/98 diesel 3.8L (much more torque than a tdi) with 750x16 tyres

It would cruise at 60/65 uphill and towing , the gearing was to deal with the 2600rpm max governed speed of the engine. The diffs were sourced from a couple of Rover P4 's

[MECCANO]

You completely bin the series mounts and they bolt to the cross member. The passenger side uses the the standard lt77 mount ( flat plate ) at the box end. with the rubber bolted to that and the moutn shown above. if that doesnt make sense i have some pics of my mk1 mounts on my other pc.

Found them:

Mk1 version

http://s2.photobucket.com/user/67fl12/media/HPIM0121.jpg.html'>

http://s2.photobucket.com/user/67fl12/media/HPIM0364.jpg.html'>

I actually have two sets of gearbox mounts, my mk1 version and some that came with the t16. Your welcome to them if they are any use. I think i might even have engine mounts to match the gearbox position for bolting in a lt77/tdi combo.

http://s2.photobucket.com/user/67fl12/media/HPIM0176.jpg.html'>

[Snagger]

If any of you guys could shove up some photos of the transmissions and their mountings, including yours, Chris, that'd be really helpful. Chris, I understand your last post to mean that your engine is in the standard Series position and the transmission extends further aft - is that right?