V5M21 / V5MT1 gear box compatibility and ratios

[PolyTek]

Hi all, and greetings from Canada. I'm a new Delica owner (L300 Exceed, Japanse Import) struggling with the ratios of the 5 speed gear box (specifically V5M21 in my case) which is not well suited for highway driving over long distances like we have here. Seems this is an issue in Aus as well. So, I'm trying to find a work-around, without getting in to re-gearing the internals. My thought is that Mistubishi vehicles made for the North American market, specifically, the Montero/Montero Sport (aka. Challenger) may have shipped with a gear ratio that would be more suited to American driving (ie. lots of long, fast, highway driving). If so, one might mate one of these gearboxes to my Delica.


First, I need to establish the gear ratios of the North American V5M transmissions. If they are the same, or insignificantly different, the mission is off.

Second, I need to establish if these transmissions are interchangeable between vehicles (Pajero, Challenger/Montero, Delica) and power plants (diesel, petrol). I think all Montero (Challenger) models sold in the US were petrol engines (2.6L and 3.0L, not sure of designations). My Delica, however, is a Japanese diesel 4D56

It would seem silly to me that transmissions with the same designation would not be compatible, but stranger things have happened.

Insight would be greatly appreciated.

Thanks in advance,
Darryl

[-Scott-]

I'm not sure what you're hoping to achieve.

If you want to drop revs at highway speeds this could be achieved by alternate diff ratios or larger tyres. Obviously, this will increase gearing in all gears, which may not be what you're after.

If you're hoping for a taller 5th gear with a similar 1st gear, I'm not sure where to find that info. Physically, you may be able to squeeze a V5MT1 where a V5M21 sits, but I doubt you'll get the V5M31 in without major surgery.

Good luck,

Scott

[NJV6]

HI there,

As per Scott- if you are after a tall cruising gear - Some of the USA Pajero's had 4.27 diff ratios. I think that'd be alot easier than changing gearbox internals.

However the Paj diff's may take some fitting under the L300.......

[PolyTek]

Thanks for your responses. Maybe I can clear this up a bit.

I am, in fact looking for a taller 5th gear, but an overall increase would suit me fine. I'm not particulairly interested in acheiving this by increasing my tire size. Any real gain this way would require a lift, and I find the Delica already a little on the high off the ground side. Changeing both the front and rear diff. would accompish this as well, but I really am looking for a drop in transmission with either a taller 5th gear, or, a taller gearing overall.

I know that some japanese vehicles are equipped with transmissions geared taller for the North American market, and was just trying to establish if this may have been the case with US Montero/Challenger V5M21/V5MT1 transmissions, and if those would be an easy swap to my deisel L300 Delica.

Thanks again guys,
Darryl

[Bitsamissin]

Very tough ask.
The V5M21 is basically a smaller box than the V5MT1.
The V5MT1 was basically behind all our 3.0 V6 engines - these boxes have a removable bellhousing which made them adaptable to other motors such as some 2.5 TDI's.
I'd doubt that any gears would be compatible between the two so your left with researching what gearing variations there were with the V5M21 boxes.
Here I can tell you that we had two final drive ratio's (5th gear) - 0.856 (91-94 Pajero's) and 0.833 (late model Tritons). According to a spreadsheet I have the V5M21 was introduced about 1990 and only had two final drive ratio's (as above) worldwide.
I've got no idea what our L200/300 had but suspect thay would be one of the two above.
Remember a V5M21 that has been under a Pajero may not necesarily work under a Delica as the shifter linkages maybe different necesitating different castings/mounts etc.
Also the US Gen 1 Pajero's with the 2.6 5sp ran a KM145 box which is essentially the same as the V5M21 but the 5sp Challenger ran the V5MT1 so that won't help you.
I would also check the 5th gear ratio of the North American Gen 1 2.6 versions and I believe you got the same model in Canada ? The internals are basically the same as the V5M21 so should be interchangeable.

[PolyTek]

Thanks for your informative reply, Bitsamissin.

I'll ponder this a bit further on the weekend when I have time to do some more research. I had hoped that the bell housings might be interchangable, making the difference between petrol/diesel and applications variation relatively easy to overcome. Once I confirm availble gear ratios (in Canada/US) I'll decide whether or not to track down another tranny, and go from there.

Cheers,
Darryl

[Rallyant]

I know Im diging up an old thread here, but,
In addition to 0.827 and 0.856, 5th Gear also came in 0.822 in the Pajero IO (montero IO)

But im interested to know how strong the V5M21 boxes are?

Also the US Gen 1 Pajero's with the 2.6 5sp ran a KM145 box which is essentially the same as the V5M21.

If its essentially the same as the KM145 im a little concerned about its strength, I run the KM145 gearbox in my NA 2.6 race car OK, But have smashed a few with the Turbo 2.6 build i had. I know the starions (starquests) had slightly wider gears in the same box on there turbo 2.6 versions, they were OK but still no good for BIG power. I know people would put the starion internals in the pajeros KM145 box for more strength.
Im wanting to do a turbo conversion ( or evo engine swap) to my Pajero IO and am wanting to check the drive line limitations (and upgrade them IF needed or possible)
( V5M21 / V5MT1 swap ?)
But maybe the V5M21 is stronger than the KM145?