so in the endless expanse of the internet at some point I came accross a manufactor that claims they rebuild the R151F 70% stronger than stock. Of course I lost that link shortly after I read it and now can't seem to find it again. I thought it was marlin crawler but searching through the website I can't seem to find that claim again. As much as I hate to admit it I'm a sucker for people making outrageous number claims like that which is reality probably don't hold up the truth. But I'd at least like to look into it. I'm currently in the planning stage of building a cummins 3.3 4runner. I've read the R151F tranny is designed to withstand 300 ftlb of torque. But that is the exactly what the cummins 3.3 puts out. So I'd rather not push it up to it's limit and get something over built for the application. Does anybody know about that? Or should I just start looking for a bigger tranny to be on the safe side, like an NV4500?

 

No matter what you do you will always have a weak link.

Go to a stronger gear box then take out axles /u joints / rears .upgrading as things go boom!!

then your back to the tranny being the weak point.

Get a good clutch set it up so the clutch slips when you do stupid.

It is not the Torque that breaks things it is how it is applied.:jessica: