Whistler RKT
New member
Hey guys,
Haven't been on the site for a year or so…hi again, Merry Christmas...anyways, picked up (rescued) a buddy's '99 SR5 (a year ago) that had been parked for 5 years and ended up in a weird predicament/scenario recently, and I'm just wondering if anyone else has ever had this problem.
The Coles notes: turns out it had a 4:10 diff up front, and a 3:91 diff in the rear, and my buddy who ordered the truck new from the Stealership in '99 never had any work done to either of the diffs. Has anyone else heard of this happening, or experienced it themselves?
The long version: The truck was really sketchy in 4Hi on snowy highways, tracking all over the place, and I couldn't figure out if the control problems were the big tires and narrow stance of the 3rd gen (coming from a 5th gen), the tires themselves (Duratracs) or maybe even the wheel spacers that I had put on that caused the control issues. (I pulled the spacers off and nothing changed.) At slower speeds it wasn't an issue, but over 80 kms, things got interesting. Also getting in and out of 4X4 was a pain in the ass. I could shift on the fly into 4Hi no problem, but in order to get out of 4X4, I had to pull over, put it in reverse, and then it would come out. Again, I just figured it was an older truck and that maybe this was normal. 2WD was no issue, except for power. Anyways, my wife was driving it last week, had it in 4X4 on snow covered back roads, and when she got onto a bare and dry highway, she shifted out of 4X4 but didn't pull over and put it in reverse to get the front diff to disengage, and less than an hour later, she was on the side of the road with smoke pouring up from under the hood after hearing a loud bang. Needless to say, the front diff met a catastrophic ending triggering off this weird set of events. So based on my door sticker, 2 separate Toyota Stealerships confirmed I had a 4:30 front diff (wrong!) so I set about finding one online (paid $350 for the diff, $400 for the install) getting a mechanic buddy to install it. All goes well with the install, except the test drive proves to be even sketchier than usual, so my buddy pulls apart the destroyed diff and informs me it wasn't a 4:30 at all, but a 4:10. (A little research on the subject after the fact, turns out the sticker issue isn't a new issue…) Fortunately, he talks me into finding another 4:30 for the rear rather than finding a 4:10 for the front, assuring me the drive will be much better, faster, better fuel economy etc with a 4:30 in the rear. So I find a rear 4:30 for $350, he installs it, and suddenly I have a new truck. Literally! Smooth as can be in 4X4, I can shift in and out of 4X4 at 80 kms no problem, no tracking or control issues. The reason being, it turns out there was a freakin' 3:91 in the rear and a 4:10 up front?
So not only am I curious whether anyone else has ever discovered this set up/screw up, but also a heads up if anyone is having issues with controllability in their truck in 4Hi, you might just have mismatched diff's like I did, apparently right out of the factory?
(And if you're curious, with the mismatched factory diff set up and a 3 inch lift and 285 Duratracs, I was struggling to get 3000 RPM's and topping out at 110 kms, and now with 4:30's front and back, I'm comfortably getting up to 3000 RPM, indicating 125 kms, and it feels like it would happily get up to 140 kms if I wanted to go there.)
One off scenario, or is there more to this that I'm missing?
Haven't been on the site for a year or so…hi again, Merry Christmas...anyways, picked up (rescued) a buddy's '99 SR5 (a year ago) that had been parked for 5 years and ended up in a weird predicament/scenario recently, and I'm just wondering if anyone else has ever had this problem.
The Coles notes: turns out it had a 4:10 diff up front, and a 3:91 diff in the rear, and my buddy who ordered the truck new from the Stealership in '99 never had any work done to either of the diffs. Has anyone else heard of this happening, or experienced it themselves?
The long version: The truck was really sketchy in 4Hi on snowy highways, tracking all over the place, and I couldn't figure out if the control problems were the big tires and narrow stance of the 3rd gen (coming from a 5th gen), the tires themselves (Duratracs) or maybe even the wheel spacers that I had put on that caused the control issues. (I pulled the spacers off and nothing changed.) At slower speeds it wasn't an issue, but over 80 kms, things got interesting. Also getting in and out of 4X4 was a pain in the ass. I could shift on the fly into 4Hi no problem, but in order to get out of 4X4, I had to pull over, put it in reverse, and then it would come out. Again, I just figured it was an older truck and that maybe this was normal. 2WD was no issue, except for power. Anyways, my wife was driving it last week, had it in 4X4 on snow covered back roads, and when she got onto a bare and dry highway, she shifted out of 4X4 but didn't pull over and put it in reverse to get the front diff to disengage, and less than an hour later, she was on the side of the road with smoke pouring up from under the hood after hearing a loud bang. Needless to say, the front diff met a catastrophic ending triggering off this weird set of events. So based on my door sticker, 2 separate Toyota Stealerships confirmed I had a 4:30 front diff (wrong!) so I set about finding one online (paid $350 for the diff, $400 for the install) getting a mechanic buddy to install it. All goes well with the install, except the test drive proves to be even sketchier than usual, so my buddy pulls apart the destroyed diff and informs me it wasn't a 4:30 at all, but a 4:10. (A little research on the subject after the fact, turns out the sticker issue isn't a new issue…) Fortunately, he talks me into finding another 4:30 for the rear rather than finding a 4:10 for the front, assuring me the drive will be much better, faster, better fuel economy etc with a 4:30 in the rear. So I find a rear 4:30 for $350, he installs it, and suddenly I have a new truck. Literally! Smooth as can be in 4X4, I can shift in and out of 4X4 at 80 kms no problem, no tracking or control issues. The reason being, it turns out there was a freakin' 3:91 in the rear and a 4:10 up front?
So not only am I curious whether anyone else has ever discovered this set up/screw up, but also a heads up if anyone is having issues with controllability in their truck in 4Hi, you might just have mismatched diff's like I did, apparently right out of the factory?
(And if you're curious, with the mismatched factory diff set up and a 3 inch lift and 285 Duratracs, I was struggling to get 3000 RPM's and topping out at 110 kms, and now with 4:30's front and back, I'm comfortably getting up to 3000 RPM, indicating 125 kms, and it feels like it would happily get up to 140 kms if I wanted to go there.)
One off scenario, or is there more to this that I'm missing?
