Anyone know the difference between 1986-1988 power steering gearboxes and 1989-1995 gearboxes? The later is obviously bigger, but does it have a different gear ratio?

After stripping my PS gearbox in my 86 4runner on the trail, I swapped in the first gearbox I could find, which was a from a 90s 4runner. It bolted right in.

 

yes, not a drastic difference but the late style is a "quicker" box

 

I believe that the ratios are different -- the later-style boxes are supposed to have a closer (tighter) steering ratio, but I'd wait for someone else to chime in.

I'm glad to hear that the later and earlier styles are interchangeable -- I was going to swap my early-style gearbox for a later one for the closer ratio, and was wondering if it was a simple bolt-up operation. Were there any additional lines you had to cap off, or anything out of the ordinary (perhaps the pitman arm was splined differently, etc.)?

 

100% interchangeable, nothing capped, remove the old, install the "new"

 

http://www.pirate4x4.com/forum/showthread.php?t=587515

 

Thanks for clarifying; I'd seen that link before when I had to replace my box, and ended up choosing one off an '87, as I wasn't sure about this line:

"The longer input gear is only an issue if you are replacing a box. If you switch from one style to the other you will need to change the length of the steering shaft that goes to the steering wheel."

I definitely wasn't up for that sort of complication, but, if I wouldn't have to toy with any of that, and could get a cheap box, I might give it a shot now!

Thanks again,
Khany2002

 

For the record, even thought the newer box has tighter ratios I wish I had the older style box. I had to change the input shaft seal and it is MUCH more difficult on the newer style box. You can change the input shaft seal on the older boxes in a matter of minutes, to change the input shaft seal on the newer boxes require that you take the whole box apart. Just my $.02