Gearbox options

[humding]

Hello All.

I have a Avant customised 6.2 NA installed in my Land Rover 110. I have had the Landrover box out 3 times in the last year with various failures. It just does not seem to be able to handle the extra torque available over a standard engine. I would like to stay with a manual box and have done a bit of searching around I have come across T56, NV4500 and NV5600. Has anybody views on these boxes, good or bad. Price seems to be a bit steep on them. Maybe an auto box would be a better proposition but what one of these would work for me. I believe some need an aftermarket controller for them. Vehicle weight is approx 2600 KG (5800 lb). When towing max total weight would be in the region of 6100kg (13600 lbs). BTW I am based in Ireland where these engines & boxes are virtually non existant so I would be looking at importing a box from the States

[trbankii]

The six-speed NV5600 would be nice, but this is a big, long, heavy box and would likely be more trouble to fit into the Rover. The NV4500 has been swapped into Jeeps, Toyotas, and such. Would likely be easier to fit than the NV5600. Can't really talk to the T56, but I'd wonder if it is stout enough to hold up to the diesel.

To the best of my knowledge, none of the manual transmissions would require a controller of any sort... Nothing electric about them... And with the 6.2, the engine wouldn't be expecting to be able to "talk" to the transmission either. An electric 6.5 originally with an automatic would expect to be able to "talk" to the transmission and you'd have to do something about that if installing a manual - I think...

[HammerWerf]

Humding,

Another transmission that lives very well behind the 6.2 is the Muncie SM-465. I've got one in my 84 C-20. good tranny, and Chevy installed them in lorries up to about 2 tonnes.

Here is a posting for one that was for sale. Good pictures to look at all sides.

http://www.pirate4x4.com/forum/showthread.php?t=454457

This link has a good description of the size of the box.

http://www.novak-adapt.com/knowledge/sm465.htm

There is also a member of TDP that has fitted a 6.2 in a Rover. Look for the name AlohaRover.

http://www.aloharovers.com/

Been a few years since I've been in Limerick. Got some family up in Mayo.

HammerWerf

[93_Burrito]

The NV5600 was only offered behind 24V Dodge Rams. Its production run was only 3 or 4 years, and there are those who say parts can be difficult and expensive to come by. Biggest obstacle with this transmission is that it has an integrated bellhousing, mating up only to the Cummins. I saw an article online somewhere about Dynatrac and another company, whose name currently escapes me, teaming together to create adapters which would allow the use of the NV5600 behind GM or Ford engines. Using such adapters would require a complete disassembly and rebuild of the transmission. The NV5600 is good ol' cast iron and tips the scales around 360 pounds.

The other 6-speed manual I'd look into would be the ZF used behind the Duramax. It's aluminum, about 240 pounds, and has what I feel to be a more user-friendly shift pattern.

[humding]

Thanks for the input. I'm afraid a four speed box is out as I had a Range Rover unit in it already. Great box but you could go most places in top gear. ZF option seems nice but I would assume a pricey option (but then again so is blowing boxes every 6 months). Is the 6.2 and the Duramax bell housing pattern the same. In other words will the ZF fit straight on to the 6.2.

Whats your views on auto's? Any sort of auto is scarse on this side of the Atlantic so I have no real experience of them myself.

[HammerWerf]

An auto that works well behind the 6.2 is the GM Turbo Hydramatic 400. It is a 3 speed box that is all mechanical( no electronics), Vacuum signal to shift. Tough box, got one in my 83CC.

GM started using that tranny in its 1.5 - 5 ton trucks, befor migrating them to the automobiles. The also sold the box to several european car makers for their use in some luxury models. Belive it or not, Rolls Royce and BMW used this truck tranny in their cars, RR up until the early 90's, I think. Don't know about the bellhouse bolt pattern for them.

Another area to check out might be some of the junk yards on the continent. might be some in there.

What are the dimensions of the old Rover box. Perhaps knowing your size limitations might help narrow down the potential list of candidates.

HammerWerf

[93_Burrito]

humding,

One real nice thing about GM truck engines is that they all utilize the same bellhousing bolt pattern. If a transmission bolts up to a 6.2L diesel, it will bolt up to a 6.5L, Duramax, 5.7L gasser so on and so forth... So yes, you can mate a ZF-6 to a 6.2L. I'd bet the cost of one is "pricey" as well.

HammerWharf's suggestion of using a TH400 is probably the cheapest way to go automatic, because it doesn't require a computer. You'd still have to figure out a way to select gears, like swapping your steering column for an automatic, or getting a floor-mounted shifter. The TH400 is a strong transmission, but it doesn't have Overdrive.

If you wanted an automatic you could look into the 700R4. This is more along the lines of a TH350, with OD. It isn't as strong as a TH400 or 4L80E, but it would give you OD and it doesn't need a computer. You'd need a way to select gears, such as swapping out the steering column for an automatic-type column or using a floor-mounted selecter.

The 4L80E. Basically the TH400, but with OD and it requires a computer to control it. You'd need a way to select gears, a place to mount the computer, and a wiring harness to complete the deal. Definitely a more expensive route than the TH400 or 700R4.

A 4x4 magazine (I may be able to find the article online...) recently swapped out a TH400 in favor of an NV4500 for their 6.2L diesel truck. They said the manual really helped wake the 6.2 up, having 2 extra gears to work the engine. The OD also increased fuel economy.

If you stay with a manual transmission, I would look into an NV4500 or a ZF-6. The 6.2 won't hurt those transmissions. They both have a granny gear and OD, and you get more power to the rear wheels with a manual over an automatic.

[ThePIGSmith]

I would like to suggest that a NV3500 maybe an option.
Yes, they are considered light/medium duty transmissions, but they can take some power.

On the television program "Trucks", Stacey David used a NV3550 in his project Crazy Horse.
That NV3550 was behind a hot 302 Ford, stroked to 349 cubic inches

http://www.staceydavid.com/client_images/staceydavid/1174483838_800x600.jpg

From my understanding, NV3500's are rated for 300hp and 300lbft in a 7500lb GVW truck.
So, I would guess that if your rig was in Daily Driver service and you do not wheel it hard or tow a 35' Airstream,
that a NV3500 would hold up to a 6.2L Diesel in a Rover.
I am sure there will others that will chime in and give a different point of point.

[Robyn]

Hello

Been thinking about your dilema.
The stick shift boxes that are strong enough to hold the diesel are usually fairly large physically.

I have used the GM TH 350 auto behind the 6.2 in a Blazer and never had any issues at all. This little beast needs only a vacuum controler to run the modulator. No electronics.
You may need/want to swap governors to get the shift points where you want them.
The 350 should be easy to find and fairly cheap. Chevy used them for many years. Even a car tranny can be used as long as you use the shorty 4x4 output shaft.

In looking towards the 4 speed boxes that are small in size the one that comes to mind is the Super T10 Borg warner.
I have seen these in Pontiac transAms back in the 70's behind the 400 inch engines and they did ok.

The vehicle plus towed weight is what's worrying me a lot with most of the smaller stick shifts like the T10.

The NV 3500 and 4500 and 5600 are well suited to handle the load and the power but to get those boxes into the little rover may prove to be problematic at best.

Personally I would check with Advance Adapters and see what is available in the way of goodies to get the different trannies to snuggle up to your transfer case.

Even if you can get a particular stick shift into the truck, if you can't buckle the T case up to it its really a moot point.
This would also go for an auto too.

Advance has a web site so ya might want to give them a look see.

The other option would of course be to swap both boxes and then rebuild the drivelines to match the new setup.

The one caviat is, which side is the front drive shaft on? you may have to use a tranny that will fit the 6.2 and a T case from another truck to get things looking at one another.

One thing for sure, as long as you can get things to physically fit it really does not make any difference whos gear box you use. Just be sure the whole package will bolt together and fit in the truck before spending your money.

Good luck
Robyn

[twaddle]

Hi Humding,
As you have found out the Land Rover manual gearboxes will not tolerate the torque of the 6.2 especially when pulling heavy trailers.
I don't have any manual gearboxes available the 5 speed models (4500 or 5600) which would be ideal but expensive, however I do have a new GM 4L80 OBD-1 1995 model. It is brand spanking new and includes a new diesel model torque convertor. If you get a hold of a suitable transfer box make sure the drive flanges will be at the same side as the Land rover diff casings. The Land Rover diffs are at the same side as the pre 88 GM 4x4 trucks were.

The 4L80 would also require a stand alone electronic control package to operate which are available at quite reasonable prices Stateside.
The 4L80 was meant for a Turboed 6.5 so the tranny will handle the 6.2 N/A torque without any problems, it is a 4 speed with lock up torque converter and the 4th speed is an overdrive ratio.
If you are interested in the 4L80 email me jim at jimmyt dot plus dot com I am located near Biggar in Scotland.
I am in the middle of clearing out the garage and workshop as we will be moving to Alberta Canada soon so let me know if this is of use to you.

Regards

Jim

[humding]

Thank you for all the info. I have been checking out Marks Adapters website in Australia and see they do adapters for TH400 and 4L80E boxes to fit the Land Rover transfer box, so at least I know now this can be done and will fit. A conversion to a manual box would probably involve doing the conversion adapter myself. A manual would still be the prefered choice but the automatic option has been done and works.Like you mention get a box that is too big and there may be problems getting the front propshaft to pass by the side of the box. One saving grace is that it is long wheel base so there is a bit more room to play with (remote t/box posibility).