4.9 gear swap complete

[macdrew77]

So I have just finished the painstaking process of swapping 4.9 gears into my 1997 SR. And I wanted to make a thread where anyone planning this swap can ask questions while the info is still fresh in my brain.

Should you consider 4.9 gears? YES. It has transformed the way this car drives, it has the power and acceleration that was lost when I went to 33” mud tires. If you have big tires I highly highly recommend re gearing and also swapping to big brake rotors off a Montero Sport.

 

[twocommas]

Did you track MPG before and after the swap?

 

[macdrew77]

A small increase of about 1-2 mpg if I keep my speed around 65mph

 

[Leeson]

I'm currently on the lookout for a set of 4.9 gears with the LSD. My truck is such a dog with 33s and being at elevation plus all the cargo. Where did you locate yours? Also how do you know whether it's the LSD, any way to tell from the VIN? From what I understand I need to look for either the 2001 or 2002 XLS to get the right 4.9s but not all are LSD. Since I don't have VSC on my '02 I really need the LSD.

 

[macdrew77]

My 1997 SR had the factory locker so I just needed the ring and pinion to swap into my carrier. I just needed to find a Montero Sport with the 3.5 and AWD, Years 2001+ I believe? Gen 3s are very rare at my local yard but Montero Sports come in all the time. It sounds like you are looking to drop the entire diffs and swap them into your truck? Should be much simpler than what I had to do, setting up the new ring and pinions in my old housings. I heard somewhere that if the truck is XLS with a sunroof it has an LSD.

 

[Leeson]

Yeah if I can locate the differentials I want then I'll just swap the whole assembly over, fairly easy.

I heard somewhere that if the truck is XLS with a sunroof it has an LSD.

Interesting, I'll keep that in mind.
It's crazy, I can find running even decent-looking 3rd gen Montero XLSs for $2000 by me. One I found nearby has a "new" 60,000 mile engine in it but the transmission is failing and they're just done putting money into it. I could buy that, swap the diffs and engine with mine and sell it for hopefully what I paid for it and get all those parts for free. Doesn't seem like too bad an idea. It also has pretty good tires on it too even.

 

[CrispyCracker]

So I have just finished the painstaking process of swapping 4.9 gears into my 1997 SR. And I wanted to make a thread where anyone planning this swap can ask questions while the info is still fresh in my brain.

Should you consider 4.9 gears? YES. It has transformed the way this car drives, it has the power and acceleration that was lost when I went to 33” mud tires. If you have big tires I highly highly recommend re gearing and also swapping to big brake rotors off a Montero Sport.

Nice work -- and good to hear that the performance is worth the time and expense. Question: based on your experience, what would you assume a shop would charge for labor (or what would you assume they'd log re: hours of work) if I provided all parts required for this switch? The 2.5 Monty I'm looking to buy already has the factory locker. Thx.