1977 Series 3 88 200tdi engine

Fitting a 200tdi to the series gearbox is the issue.. The torque is too great for the series gearbox. e.g, having the power to Pull up steep hills in top gear puts far to much stress through the gearbox. The low range gearing with 4.7 :1 axels will be much lower with a defender gearbox but its high range, will be similar as the series has an underdrive of 1.15:1 and 1.2:1 on the Defender.
The 3.5:1 diffs of the Defender give the higher gearing, but its the 3.5 axel ratios that'll blow the series gearboxes even quicker... There are plenty of people who've done this conversion to testify..
However, If you fitted the 200tdi engine with its gearbox and perm 4x4 transfer box, you'll have solved the main weak gearbox issue, Just Modify the chassis where needed to fit.
As it'll be perm 4WD, you'd need to keep Diff lock engaged but you can use with the series UJ front axel, provided you run with front FWH's disengaged., then you won't need CV joints in the front axel.
Fit a stronger 4 pinion Dana Salisbury rear axel and you wont break half shafts.
With 4.7:1 diffs you'll have even lower gearing, especially in Low Range (which is Nice), while feeling ungeared in high Range. Yet in top gear, with a 0.75:1 overdrive, the final drive ratios of the Series/Defender are very similar.
Juggle position of engine/ gearbox and modified Prop shaft lengths to suit would appear the most effective method..
So why not Keep the Defender Engine and box together.

Been driving a TDI powered series for fifteen years, changing the gear oil every four thousand miles, still going. And I'm not gentle, I use the turner performance head and the updated IP. And I tow with it too.

Wildefalcon said:

Been driving a TDI powered series for fifteen years, changing the gear oil every four thousand miles, still going. And I'm not gentle, I use the turner performance head and the updated IP. And I tow with it too.

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That is impressive to hear.. Do you have standard 4.7:1 diffs?
I can't see why there should be gearbox issues there are, but I know when I had a Perkin 4236 the series gearbox couldn't handle the torque

Enrich01 said:

Fitting a 200tdi to the series gearbox is the issue.. The torque is too great for the series gearbox. e

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Loads and loads of people have run Tdi's and more powerful V8's in Series vehicles for decades. Poor driving or a worn gearbox might cause problems. But I'd wager the vast majority survive perfectly fine.

Enrich01 said:

The low range gearing with 4.7 :1 axels will be much lower with a defender gearbox but its high range, will be similar as the series has an underdrive of 1.15:1 and 1.2:1 on the Defender.

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If you are meaning an LT230 transfer box, then a Defender would be 1.4:1 unless it was a factory V8 then it would be 1.192:1 Range Rovers and Discovery 1's use the 1.211:1 transfer box.

However fitting an LT-77 and LT-230 is vastly more work and makes the vehicle way less Series like.

As you say, driven correctly the series Box may cope well..
With 200tdi's, Most people add higher ratio diffs or a high ratio transfer box which then overloads the series main box.
A 200tdi puts out twice the torque the series box was designed to handle.
There are countless 200tdi forum sagas of series gearbox woes. Fully rebuilt gearboxes stripping teeth off the 3rd gear wheel in less than 5000 miles, to Fully rebuilt boxes having 3rd/4th Syncro hub bearing failure.
To be fair, over gearing of the final drives is usually the cause. So if the 4.7:1 diffs are retained with standard ratio high of 1.15:1 then I can see the box lasting much longer.
But From the sagas I've read, many give up the 200tdi's and revert to a 200di or similar.

Enrich01 said:

As you say, driven correctly the series Box may cope well..
With 200tdi's, Most people add higher ratio diffs or a high ratio transfer box which then overloads the series main box.
A 200tdi puts out twice the torque the series box was designed to handle.
There are countless 200tdi forum sagas of series gearbox woes. Fully rebuilt gearboxes stripping teeth off the 3rd gear wheel in less than 5000 miles, to Fully rebuilt boxes having 3rd/4th Syncro hub bearing failure.
To be fair, over gearing of the final drives is usually the cause. So if the 4.7:1 diffs are retained with standard ratio high of 1.15:1 then I can see the box lasting much longer.
But From the sagas I've read, many give up the 200tdi's and revert to a 200di or similar.

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Don't take this personally, but I ran an S111 with 200tdi, overdrive and 3.5 diffs for three years. I didn't drive it gently, did drive it flat out on motorways, but did use the gears a lot. No bits fell out of either box.

Enrich01 said:

As it'll be perm 4WD, you'd need to keep Diff lock engaged but you can use with the series UJ front axel, provided you run with front FWH's disengaged., then you won't need CV joints in the front axel.

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I can understand that if you switched the FW hubs 'off' you'd need difflock, but not otherwise?

And if you took the CVs out you wouldn't need the FW hubs, but why on earth would you?

Only the stage 1v8 and the 101 had CV front axles. Excepting the tracta jointed early series 1, all other series had UJ axles, so in centre locked differential would be uncomfortable to drive on the road. In open centre diff, they might be okay, but I've no experience of that.

boguing said:

I can understand that if you switched the FW hubs 'off' you'd need difflock, but not otherwise?

And if you took the CVs out you wouldn't need the FW hubs, but why on earth would you?

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The tracta jointed front axels fitted as standard to Series part time 4wds wont work with a perm 4x4 transmission. Without CV joints in the front swivels, the front tyres will scrub, and not turn evenly.
So with Series axels, I'd disengage the FWHs on the front axel, and engage centre Diff lock. Then you can send all the drive to the Rear axel only, while the front prop turns but with the front wheel drive disconnected.
Fit a Salisbury rear axel and eliminates all the series Gearbox woes.

Tracta joints haven't been used since the 1940's. They use universal joints. And the diff has no impact on gearbox longevity.

Enrich01 said:

The tracta jointed front axels fitted as standard to Series part time 4wds wont work with a perm 4x4 transmission. Without CV joints in the front swivels, the front tyres will scrub, and not turn evenly.
So with Series axels, I'd disengage the FWHs on the front axel, and engage centre Diff lock. Then you can send all the drive to the Rear axel only, while the front prop turns but with the front wheel drive disconnected.
Fit a Salisbury rear axel and eliminates all the series Gearbox woes.

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Thanks, that makes sense. (Still say that series boxes aren't as bad as you think though!).

Wildefalcon said:

Tracta joints haven't been used since the 1940's. They use universal joints. And the diff has no impact on gearbox longevity.

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I assumed he meant UJs.

As For fitting a 200tdi behind a series Gearbox, here are some of the issues encountered, by very well engineered conversions.


Yes my mistake.. Tracta Joints were only used on the 48-51 series ones. The same joints as used in the Willy's Jeep

Enrich01 said:

As you say, driven correctly the series Box may cope well..
With 200tdi's, Most people add higher ratio diffs or a high ratio transfer box which then overloads the series main box.
A 200tdi puts out twice the torque the series box was designed to handle.
There are countless 200tdi forum sagas of series gearbox woes. Fully rebuilt gearboxes stripping teeth off the 3rd gear wheel in less than 5000 miles, to Fully rebuilt boxes having 3rd/4th Syncro hub bearing failure.
To be fair, over gearing of the final drives is usually the cause. So if the 4.7:1 diffs are retained with standard ratio high of 1.15:1 then I can see the box lasting much longer.
But From the sagas I've read, many give up the 200tdi's and revert to a 200di or similar.

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Not convinced the box is not up to the task. I had a Series with a 200Tdi. Driven hard enough to catch a pack of Lotus Elsie’s around the Elan valley and even a lap of the Silverstone GP circuit. Originally on 4.7 diffs although did swap to 3.54’s. Did a diff and half shaft in setting up some off trials events. Althout I planned to return to 4.7 diffs and an OD unit. But sadly had to sell the vehicle.

I know of a couple of other Tdi powered Series vehicles and a few V8 ones. None have had gearbox issues.

Enrich01 said:

The tracta jointed front axels fitted as standard to Series part time 4wds wont work with a perm 4x4 transmission. Without CV joints in the front swivels, the front tyres will scrub, and not turn evenly.
So with Series axels, I'd disengage the FWHs on the front axel, and engage centre Diff lock. Then you can send all the drive to the Rear axel only, while the front prop turns but with the front wheel drive disconnected.
Fit a Salisbury rear axel and eliminates all the series Gearbox woes.

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S1 are the tracta joints and I think that was just the early ones, s2/2a and 3 have u/js.

Enrich01 said:

As you say, driven correctly the series Box may cope well..
With 200tdi's, Most people add higher ratio diffs or a high ratio transfer box which then overloads the series main box.
A 200tdi puts out twice the torque the series box was designed to handle.
There are countless 200tdi forum sagas of series gearbox woes. Fully rebuilt gearboxes stripping teeth off the 3rd gear wheel in less than 5000 miles, to Fully rebuilt boxes having 3rd/4th Syncro hub bearing failure.
To be fair, over gearing of the final drives is usually the cause. So if the 4.7:1 diffs are retained with standard ratio high of 1.15:1 then I can see the box lasting much longer.
But From the sagas I've read, many give up the 200tdi's and revert to a 200di or similar.

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Hand on heart I do not drive any of my vehicles correctly, including my s2 88 with 200tdi conversion and 3.5 diffs.
Think the 200tdi engine has been in there over 10 years now.

Go up a steep hill off road and the front of the gbox grumbles, but it also did this with the previous 2.0 diesel!

Replacing a knackered engine doesn't miraculously make the gearbox brand new. I think a good late series 3 box is strong enough to take a TDI for the remaining life of the vehicle, which isn't likely to be commuting or working.

lynall said:

S1 are the tracta joints and I think that was just the early ones, s2/2a and 3 have u/js.

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Yes, my mistake. tracta jointed front half shafts were only used on early 48-51 series ones..
As same as used on the Willy's jeep, that Rover, as we know, emulated with their limited post war resources.
I wonder if the front axel components were the same.. i.e Dana sourced items, or built their own?

Wildefalcon said:

Replacing a knackered engine doesn't miraculously make the gearbox brand new. I think a good late series 3 box is strong enough to take a TDI for the remaining life of the vehicle, which isn't likely to be commuting or working.

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It is fine if the tdi is as knackered as the 2.0 I took out, she breathes like a steam train on heat!
Great engines even when shagged.

Enrich01 said:

I can't see why there should be gearbox issues there are, but I know when I had a Perkin 4236 the series gearbox couldn't handle the torque

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The Perkins 4236 may not rate high in the HP section but is a Beast when it comes torque which is at its max at just 1300 rpm