Gearing

[pbkid]

ok, i know i havent posted much here lately (at least not anything serious), but i need some technical advice from my friends....

lets see who can help me figure this out.

1. I had my rear diff replaced in july at a shop in california, while they were in there replacing the ring and pinion i figured it was a good time to change the gearing out..... so, i went ahead and told them to put 4.88's in.

2. While it was in the shop there, it took them 3 tries to get the rear diff working, without massive backlash or bad whine...

3. they called me 4 months later to tell me that they had 'mistakenly' put the wrong fluid in some cars, so i should change mine ASAP (of course this is after i drove 1500 miles home :rolly2:)

4. i havent driven the car since they told me to change the fluid... basically because its cheaper to drive my acura (35mpg) than the 4runner.

5. i got my Yeti re-insured about a month ago due to winter approaching fast here in colorado and immediately changed my rear diff fluid. Of course to find some 'interesting' fluid in there. The first 1/3 of the fluid came out metallic silver (looked like unicorn blood) and had the consistency of hot syrup. then the other 2/3 came out regular color, smell and appearance for diff fluid. (yes, i saved the first 1/3 of the fluid in a jar for legal purposes incase my rear end is f*$ked)

so.......2 questions....

1. for anyone who has changed gearing before, does this 'unicorn blood' seem ok or should i REALLY be worried and start working on serving the shop?

2. my more immediate and important question- My new front diff is in the mail currently, on its way to me to be installed (ordered 4.88's)..... with all the problems i had with this shop, i wanted to check and make sure that the gears they put in the rear are, in fact, 4.88's.... anyone know of a way to check this without taking the rear end apart???

My dad suggested- jack up the whole rear end, manually turn the driveshaft (maybe 20 times) and count rotations of the tires.... then install the front and do the same procedure... if the ratio of driveshaft rotations matches the tire rotations then the gearing is the same. That makes logical sense to me, but i thought i would get your guys' input and see if you know if other ways to double check the gearing?

[Ldub]

dunno (OK, can't remember) if toys are a third member setup like zu's, or if the diffs have a cover, but dividing the number of teeth on the ring, by the number of teeth on the pinion = ratio

or look'ee here...:smilewink

http://www.5speedtransmissions.com/determine_gear_ratio.html

[Triathlete]

Toys should be a third. But an easier way is to just disconnect the drive shaft and turn the pinion, for every 1 turn the axles should turn 4.88 times (or just the opposite).
You should ask the shop exactly what it was they put in there and what it should look like when it comes out...then you will have more to go on and maybe peace of mind (or not).

[PK]

Jack, sorry mate, but that silver unicorn blood is not good news.

Pass a good magnet through the fluid, and I bet a lot of metal will stick to the magnet.

Something in there is foobarred.

I would be getting back in touch with that shop real quick.
At least they did follow up and advise you, so they might have some integrity and pay up to put it right.

As far as checking your ratio goes, your dad's suggestion is the easiest way.
Accurately mark a reference point on the tailshaft and the diff housing.
Also one on the wheel and guard.
Turn the wheel exactly 1 turn, count the number of turns the tailshaft makes, and the incomplete turn is the .88 (hopefully) you are looking for.

Hope you get out of this OK.

PK

[pbkid]

ok, here's an update, for those who care lol.

called the shop who installed the gears in july. They said that the 'bad fluid' they received was, in fact, just contaminated oil, but it was the correct weight, and it was definately gear fluid. i asked him why it would be 'unicorn blood' colored and he said that it was probably just some leftover flaking that had settled since my car sat for months over the summer. he said normally you wouldnt notice it, but because it had time to settle and i didnt drive it before i changed the fluid, thats why it looked so bad. Furthermore, he said that since i havent noticed any kind of bearing whine or any odd noises for that matter, its fine.

ill call a local shop here in colorado (that doesnt have any reason to make me believe its fine) next week to verify this stuff, but it was definately relieving.

[Triathlete]

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[Ascinder]

Any time parts make metal, it's a bad thing. I'd ask them what they plan to do if your diff ever grenades. And get it in writing.