Best alternative to the T-90 tranny?

JeepMkd · 13th February 2010, 07:10

Well, I had been thinking lately about changing my tired 3-speed transmission. It's the stock T-90 with the T-18 t-case. Too slow due to low diesel rpm and therefore too noisy.

Can you tell me which is the best option without a lot of modification? I want the new unit to fit in the same spots as the old one. As far as I have researched, I found out that the KMT90 is the one I should search for.

This is what I'm thinking - 4 speed transmission from the Mahindra Kz4x4 (assembled in Greece). This transmission fits perfectly, it's nearly the same shape and also has the transfer case with it. I have a 2.3 Sierra engine, whose engine block is identical to the Peugeot one used by the Kz4x4, so it fits on the 3 bolts and also the starter is not a problem. Prop-shafts won't need modifying and the hand brake just needs fitting the cable.

I found these photos on the Mahindra Register, an English Mahindra enthusiasts page. Is this a proper replacement for my T-90? The model is Indian Chief from 1996, so assume the Kz4x4 uses the same unit. If this is the case, I can easily track one in Greece and go get it.
I'd appreciate your input.

ex670c · 13th February 2010, 11:27

Hi JEEPMkd,

What Engine do you have?

M&M Vehicles used the 3 Speed with the following engines
i) F4-134
ii) B275 aka MD2350
iii) XDP4.9
iv) Lombardini 9hp.

To convert a 3 Speed to 4 Speed you will need
i) 4 Speed Bell-Housing specific to the engine
ii) 4 Speed G-Box & T-Case

The 4 Speed G Box is longer than the 3 Speed, so you will have to push the cross member back a few inches (2-3)

This will effect the length of you propeller shafts
i) Front Prop-Shaft has to be lengthened
ii) Rear Prop-Shaft has to be shortened.

Regards,

Arka

SPIKE ARRESTOR · 13th February 2010, 11:37

@ Arka you will have to push the cross member back by 1 and 15/64 inches, i suppose Behram Sir had done this design for CJ4A,
@JeepMkd PM him for more details.

Hope this clarifies.

Spike

star_aqua · 13th February 2010, 13:00

Quote:

Originally Posted by ex670c

Hi JEEPMkd,

What Engine do you have?

Arka, He has XD2 engine from peugeot which is a 2.3ltr engine and looks exactly similar to XD3P block. so no issues with mating KMT90.

JeepMkd · 21st February 2010, 16:55

What transmission does the 540 use? I know it's 4 speed, but will it fit my Mahindra?

JeepCaptain · 21st February 2010, 18:05

Quote:

Originally Posted by SPIKE ARRESTOR

@ Arka you will have to push the cross member back by 1 and 15/64 inches, i suppose Behram Sir had done this design for CJ4A,
@JeepMkd PM him for more details.

Hope this clarifies.

Spike

Spike, JeepMkd is also having a export version CJ4A.

Quote:

Originally Posted by JeepMkd

What transmission does the 540 use? I know it's 4 speed, but will it fit my Mahindra?

Mite,
How you doing friend. Hope you are having fun with your Jeep in snow. Post recents pics if you have any.

Coming back to your question - Mahindra MM540 uses KMT90 4 speed GB.

JeepMkd · 21st February 2010, 18:37

Quote:

Originally Posted by JeepCaptain

Mite,
How you doing friend. Hope you are having fun with your Jeep in snow. Post recents pics if you have any.

Coming back to your question - Mahindra MM540 uses KMT90 4 speed GB.

Well, very little snow this year. Maximum was 3 inches and lasted only for a day. Other parts of the country got burried in 2ft however... And the worst part is that my transmission is on its last leg, so now I'm shopping for a KMT90.

JeepCaptain · 21st February 2010, 19:09

Quote:

Originally Posted by JeepMkd

Well, very little snow this year. Maximum was 3 inches and lasted only for a day. Other parts of the country got burried in 2ft however... And the worst part is that my transmission is on its last leg, so now I'm shopping for a KMT90.

Mite, what is the advantage you are expecting with this GB swap.

AFAIK the final ratios are same on T90 and KMT90. Experts correct me if I am wrong.

In that case may be you can just settle for a GB rebuild. And parts are easily available in India. If you want I can help you get the parts. But dont know how expensive are the shipping charges and customs duty in your country.
Shibu

JeepMkd · 25th February 2010, 16:48

Guys, I have another question

Will the handbrake drum from the T-90 fit the KMT90. I think it will, but what's with the prop shafts (driveshafts)? Do they connect in a same way? Leghtening or shortening them is not a problem.

Quote:

Originally Posted by JeepCaptain

Mite, what is the advantage you are expecting with this GB swap.

AFAIK the final ratios are same on T90 and KMT90. Experts correct me if I am wrong.

In that case may be you can just settle for a GB rebuild. And parts are easily available in India. If you want I can help you get the parts. But dont know how expensive are the shipping charges and customs duty in your country.
Shibu

I know that it would be a lot cheaper just to rebuild the tranny, but I don't have any parts and international shipping is a PITA. First of all, it will be more expensive than the parts, and being gears and stuff it will be a problem at the customs and from the charges you'll get a heart attack

My father opted for this conversion since the diesel is in, we just didn't have the time, the finances and the parts to do it. I feel like now is the moment because it's possible and that the original transmission is gone. If it had been OK, I wouldn't have changed it.

Top speed will increase, but that's the last reason why we're trying to do this.
The diesel works at a lot lower RPMs than the petrol and the 3 speed are killing it. Top speed is now 60kms and in places where we were driving a Mahindra KZ4x4 in 2nd and 3rd, we are driving ours with 1st gear (on the asphalt that is). It's slow, it's noisy and the diesel is struggling.
Also, it wouldn't affect the driveability and performance off road because the ratios are nearly the same and so far I'm very pleased with the quality and ruggedness of the Mahindra parts.

Once the T-90 is out, we will open it and probably at some point in the future rebuild it. I still have the Hurricane, so they might be a part of a another Mahindra or Willys project. Simply if life allows they'll go back where they came from and make my Jeep 100% original

ex670c · 25th February 2010, 18:19

Hi JeepMkd,

T-90
1st 2.798:1
2nd 1.551:1
3rd 1.000:1
Rev 3.798:1

Lower Ratio T-90 (optional)
1st 3.339:1
2nd 1.851:1
3rd 1.000:1
Rev 4.531:1

KMT-90
1st 3.986:1
2nd 2.368:1
3rd 1.473:1
4th 1.000:1
Rev 5.315:1

What is your Differential Ratio? (5.38:1 or 4.27:1)

You can interchange the Hand Brake and Propeller Shaft Yoke/Companion Flange.

Regards,

Arka

JeepMkd · 25th February 2010, 20:54

Arka, according to my Service Manual (printed in 1968

) the gear ratios on the differentials are 5.38:1 both the rear and front of course.

Edit:
Transmission ratios are:
1st 2.798:1
2nd 1.551:1
3rd 1.000:1
Reverse 3.798:1

13th February 2010, 07:10	#1
JeepMkd BHPian Join Date: Feb 2009 Location: Republic of MACEDONIA Posts: 86 Thanked: 3 Times	Best alternative to the T-90 tranny? Well, I had been thinking lately about changing my tired 3-speed transmission. It's the stock T-90 with the T-18 t-case. Too slow due to low diesel rpm and therefore too noisy. Can you tell me which is the best option without a lot of modification? I want the new unit to fit in the same spots as the old one. As far as I have researched, I found out that the KMT90 is the one I should search for. This is what I'm thinking - 4 speed transmission from the Mahindra Kz4x4 (assembled in Greece). This transmission fits perfectly, it's nearly the same shape and also has the transfer case with it. I have a 2.3 Sierra engine, whose engine block is identical to the Peugeot one used by the Kz4x4, so it fits on the 3 bolts and also the starter is not a problem. Prop-shafts won't need modifying and the hand brake just needs fitting the cable. I found these photos on the Mahindra Register, an English Mahindra enthusiasts page. Is this a proper replacement for my T-90? The model is Indian Chief from 1996, so assume the Kz4x4 uses the same unit. If this is the case, I can easily track one in Greece and go get it. I'd appreciate your input. Attached Thumbnails Last edited by JeepMkd : 13th February 2010 at 07:14.
	() Thanks

13th February 2010, 11:27	#2
ex670c Senior - BHPian Join Date: Nov 2004 Location: Chennai Posts: 2,470 Thanked: 2,170 Times View My Garage	3 Speed to 4 Speed Hi JEEPMkd, What Engine do you have? M&M Vehicles used the 3 Speed with the following engines i) F4-134 ii) B275 aka MD2350 iii) XDP4.9 iv) Lombardini 9hp. To convert a 3 Speed to 4 Speed you will need i) 4 Speed Bell-Housing specific to the engine ii) 4 Speed G-Box & T-Case The 4 Speed G Box is longer than the 3 Speed, so you will have to push the cross member back a few inches (2-3) This will effect the length of you propeller shafts i) Front Prop-Shaft has to be lengthened ii) Rear Prop-Shaft has to be shortened. Regards, Arka
	() Thanks

13th February 2010, 11:37	#3
SPIKE ARRESTOR Senior - BHPian Join Date: Nov 2009 Location: Germany Posts: 2,856 Thanked: 1,545 Times	@ Arka you will have to push the cross member back by 1 and 15/64 inches, i suppose Behram Sir had done this design for CJ4A, @JeepMkd PM him for more details. Hope this clarifies. Spike
	() Thanks

21st February 2010, 16:55	#5
JeepMkd BHPian Join Date: Feb 2009 Location: Republic of MACEDONIA Posts: 86 Thanked: 3 Times	What transmission does the 540 use? I know it's 4 speed, but will it fit my Mahindra?
	() Thanks

25th February 2010, 18:19	#10
ex670c Senior - BHPian Join Date: Nov 2004 Location: Chennai Posts: 2,470 Thanked: 2,170 Times View My Garage	Gear Ratios Hi JeepMkd, T-90 1st 2.798:1 2nd 1.551:1 3rd 1.000:1 Rev 3.798:1 Lower Ratio T-90 (optional) 1st 3.339:1 2nd 1.851:1 3rd 1.000:1 Rev 4.531:1 KMT-90 1st 3.986:1 2nd 2.368:1 3rd 1.473:1 4th 1.000:1 Rev 5.315:1 What is your Differential Ratio? (5.38:1 or 4.27:1) You can interchange the Hand Brake and Propeller Shaft Yoke/Companion Flange. Regards, Arka
	() Thanks

25th February 2010, 20:54	#11
JeepMkd BHPian Join Date: Feb 2009 Location: Republic of MACEDONIA Posts: 86 Thanked: 3 Times	Arka, according to my Service Manual (printed in 1968 ) the gear ratios on the differentials are 5.38:1 both the rear and front of course. Edit: Transmission ratios are: 1st 2.798:1 2nd 1.551:1 3rd 1.000:1 Reverse 3.798:1 Last edited by JeepMkd : 25th February 2010 at 20:59.
	() Thanks