Topic: 4.30 front 4.37 rear...

[H8PVMNT]

I got a couple 4 cyl thirds I'd like to freshen up and run this winter on my 4Runner. One is a 4.30 out of the 4 cyl auto trans and the other is the 4.375 out of a 1980 pickup.  I was thinking the 4.30 up front and the 4.37 rear would have a slight, but cool thrust effect for snow wheeling.  In anyone's experience can we get away with this tiny difference in ratio front to rear with the toyota t-case as long as we keep it on low traction?  I know ford did it for years but I've never heard of it being done on a toyota.  We are looking at about a 1.71% difference based on my calculations...

[Nimyad]

Ford did 4.11 front and 4.10 rear, this supposedly helped pull the trucks through obstacles better. So if your going to do it I'd put the 4.37 front and 4.30 rear, this will do what Ford said and also make steering easier than if you did 4.37 in the rear.

[H8PVMNT [OP]]

Yeah but the 4.30 is the higher ratio, so if you want the front end to pull you would need the 4.30 front and the 4.37 in the back otherwise you would be pushing the front and it would want to get the back end out on you.

I vistited wuth ZUK on it and he said the 4.30 front/4.37 rear was the way to go.  He had 5.38 front and 5.29 rear, which is the other way around with the higher ratio to the rear and apparently it had a slight negative effect on handling.

[twistedtoy92]

You've got the right idea going, 4.30 front an 4.37 rear. In reality it will feel damn near the same as running the same ratios f/r if they are open diffs. spiders will take up the difference but if its locked in the rear you might feel it potentially drag in the rear and vice versa.... Run it and post up youre results! got me curious now!

[H8PVMNT [OP]]

It's welded rear and aussied front.  I will post up results.

[Nimyad]

Yeah but the 4.30 is the higher ratio, so if you want the front end to pull you would need the 4.30 front and the 4.37 in the back otherwise you would be pushing the front and it would want to get the back end out on you.

I vistited wuth ZUK on it and he said the 4.30 front/4.37 rear was the way to go.  He had 5.38 front and 5.29 rear, which is the other way around with the higher ratio to the rear and apparently it had a slight negative effect on handling.

Makes sense, it's tricky to sit and think about. Definitely post up your results!

[H8PVMNT [OP]]

Yeah I'm really curious how it works.  I may feel no percievable difference but it's a theorey.

So far I have them in but I haven't had a chance to wheel at all.  The 4.37 rear ratio feels pretty good with the 3RZ and 35s though. A 22re would be falling on it's face for sure.

I would have to say that 4.56 would probably be the best for this setup but I can use 5th and everything, we have pulled a trailor and it was no difference from pulling with 5.29s, just that you shifted at different times. Oddly I can pull hills better with the 4.37s than with the 5.29s because I tend to be in 3rd rather than trying to milk out 4th because 3rd was to slow, which is just what I was hoping for.

It's nice to know when you have more in the engine department you can break the gearing rules a little and it still works OK.  The real point of this whole thing is to find something that works that I can scavenge off of wrecks and other peoples take offs so I can keep the truck going over time with cheap, plentiful used bits rather than haveing to slap down $250 every time I need a ring and pinion.

[H8PVMNT [OP]]

We got to wheel a trials comp with it and there were lots of switchback turns in soft dirt.  The slightly higher front ratio seems to help you pivot the turns almost like a slight front dig when you give it a little throttle.

This photo is not an example of this effect, just a pic from the competition...  Check out my kid spotting for my wife!  He really gets it she took 5th out of 17 drivers...

[kneedownnate]

I have the opposite in my 80 after breaking my last 4.37 and the truck hates it.  Will be swapping out both to 5.29 soon

[H8PVMNT [OP]]

I got to drive in on some thick road snow pack this week and the slightly higher front ratio works great.  Pulls you strait kind of like a front wheel drive car.  You can really pivot the sharp low speed turns with a little throttle application.  I haven't got to de any deep snow wheeling with it yet but I will post up as soon as I do.

I think having the higher gears up front is the whole key to this working out.  It would totally suck if the rear end was pushing instead of the front pulling.