Budbuilt Tummy Tuck with Extras!! (1 Viewer)

[BoxOnWheels]

I'm a Blue Room forum regular so I don't post here much. But I figured some of you might be interested in seeing some of the upgrades that Bud performed on my FJ Cruiser last October. The article includes lots of pictures and even provides some of the initial prototyping photos for the rear differential skid, lower link skid, and more!

Inchworm Lefty Install: FJ Cruiser Gets a Tummy Tuck


Cheers,

Jeff

 

[Mtbcoach]

Glad you found the place, welcome...

Nice write up on the mod...

 

[BoxOnWheels]

Ha, ha... what can I say? I guess I'm just a one-forum kind of guy.

The write up was loooong overdue, but thanks.

So how's your hardware holding up these days? Just noticed FJNewb posted about Lefty gear problems. I'm wondering if this is a fluke or to be expected.

 

[FJNewb]

I don't think it is a fluke. I know several output shafts had failed orginally on the Lefty and thats why they started offering them with 30 spline chromoly outputs. I think all this has done is move the failure point from the output shaft to the 4Lo gear set. Instead of the CV giving way the 4Lo gear sets seem to be.

I know my case was the 3rd or 4th to have the 4Lo gears go. I'm not sure why they haven't been mentioning to lefty buyers that you could upgrade to chromoly 4Lo gears for $125 which gives you a 40% increase in yeild strength...well worth the money. I think Marlin plans to use the chromoly gears in all future lefty cases going into heavier higher hp vehicles (FJ, 4Runner, Tacoma). Inchworm was clueless and didn't even know Chromoly 4Lo gears from Marlin were even an option. I've found Marlin's customer service to be superior to Inchworms....even though the product was inchworms which is pretty impressive.


Btw - for your setup with the S/C what did Bud change on the cross member? I was looking at mine trying to figure out how you were actually managing to rotate the case under load causing it to knock off the tunnel?

 

[BoxOnWheels]

I'm not sure why they haven't been mentioning to lefty buyers that you could upgrade to chromoly 4Lo gears for $125 which gives you a 40% increase in yeild strength...well worth the money.

Btw - for your setup with the S/C what did Bud change on the cross member? I was looking at mine trying to figure out how you were actually managing to rotate the case under load causing it to knock off the tunnel?

I completely agree with the upgrade comment. I would have definitely upgraded if I had known there was an option.

It wasn't just the case that was rotating. The FJ's fluid-filled motor mounts allow for an unbelievable amount of movement when the engine is under load. The entire drive train was twisting more than expected as a result of the added torque from the supercharger. That combined with the fact that the new cross member was so much higher than stock caused the Lefty to make contact with the side of the tunnel. Bud had the new cross member designed with two different sets of transmission mounting holes but now that I look at the photos, it appears that he used the original holes. So it must have just been the combination of punching out the tunnel a bit more and lowering the cross member overall that did the trick. Based on what I remember about the cross member side mounts, he must have had the holes cut slightly higher in the side flanges (of the new cross member) to allow for the additional drop.

I actually added a few extra photos at the end of the article that show the cross member in more detail if it helps.

 

[BoxOnWheels]

...you could upgrade to chromoly 4Lo gears for $125 which gives you a 40% increase in yeild strength...I think Marlin plans to use the chromoly gears in all future lefty cases going into heavier higher hp vehicles

I spoke with Inchworm recently and was told that Marlin was no longer offering the chromoly gear sets. They have a few left from the original run but after those are gone they are no longer selling them. Apparently, producing them was cost prohibitive. Of course, this is via Inchworm. I haven't spoken to Marlin directly yet to confirm. Bit of a shame if it's true though, especially if the XD gears aren't up to the task long term.

BTW, I just finished replacing my rear output seal again. It's been about a year since the last one blew. Why can't this stuff happen in the Spring or Summer instead of when it's 15 degrees outside?