I'm going to install my 3.55 gears this weekend, What to look out for?

Starscream88

New Member
Mar 8, 2003
1,277
1
0
Park Ridge NJ
Ok,

Have 3.08's now,

Have bought and need to install my 3.55's
I have a new bearing on the pinion, and a new crush collar,
Im planning on doing this,

Taking it all out,
Leaving the shims alone and not touching the posi unit,
Putting it all back together and pray I don't get any problems,



BUT
Lets say I DO get problems, like whining etc, I can always shim it later on, OR worse comes to worse install the old gears again,

SO
How many people have found going from 3.08 to 3.55 and not needing to re-shim?
 
i went from 3.08 to 3.73 and had to add about .006" of shim, i still have a little buzz at 55-60 mph but not enough to concern me. the biggest problem is setting your pinion depth correctly. if your measurements are precise and you use the same location to measure from, you shouldn't have a problem setting it. good luck!
 
oh, and make sure to add friction modifier when you put it back together!! ford has it for about $10 a bottle (i think the reference # is XL-7) or BG makes some stuff called LS-2 if you can find it. Lucas also has an additive, but I have never used it.
 
Just so were on the same track how do you set the pinion depth?

I was told if you go from Ford gears to Ford gears you dont have to do anything to the pinion,
It just takes the same place as the one that was there

The bearings already on the new set, so where do you set it?
 
the pinion should be set if the shim was already on the new one when you had the bearing pressed on. measure from the head of the old pinion to the edge of the housing with a micrometer or dial caliper, then try to set the new one exactly as the old one was. sounds more complicated than it really is, but if the depth is wrong the wear pattern will be screwy. if you do have to change the shim on the pinion you have to have the bearing pressed back off and back on :(
 
oh crap,

I dont even have any shims,
Just a set of gears, and a new crush collar and pinion nut,
I could get a bearing puller from sears tomorrow,

I heard if you boil the bearing in hot water for 5 mins you can slip it on the pinion and it will slide all the way down and dosent need to be pressed on,

Is there much difference with shim thickness of 3.08 and 3.55?
Or is it a case by case basis?
Im worried now
 
don't be worried so much. if you notice noise, just reshim it in the first 500 miles or so (unless it's horribly misaligned). ford racing gears are known for their ease of install...the hardest part of mine was lifting the diff from the floor into the housing...that's a heavy chunk of steel
 
More than likely it will whine though right?

I thought as im not stepping up the gears that much I should be ok with the stock shims,

I hope everything goes according to plan.

BTW whats the easiest way to crush the crush collar,
I heard they were REALLY hard to crush,

Should I start the crush with a impact gun?
Or would a breaker bar be ok?
 
i held the yoke with a 3 foot pipe wrench while my stepfather torqued with a 1/2" 2 foot torque wrench. You should try to avoid using an impact if possible because you could overdo it. It is best to have someone hold the yoke and do it by hand, but you really have to put some ass behind it!!
 
listen up dude dont boil anything,give it heat with a torch to take off and it ill come off like if it has soap,then get a small stove and place bearing over stove(make sure its small cause youll need it next to you unless you re doing it in the kitchen)and once again it will go in like it has soap,but you guys are forgeting about backlash,its not a oil change if you know what i mean and youll need and inpact gun for that crush shim on the pinion
 
its the only thing ive left to instal,

ive been busy with everything else, now I have time to put these in

I also have to replace my clutch this weekend,

I guess ill do the clutch, and buy a shim kit,
i think this job I only want to do once :)
 
the only ford rearend ive ever done any serious work to was a 9 inch, but ive rebuilt many a chevy rearends(for certain reasons). for the spacing of the pinion there should have some numbers on them eg. like a +3 or a -4 that would mean that the pinion is plus 3 thousanths in measurement( from bluprint standards) from the carrier or minus 4. another way they do it is to give the exact measurement like 2.503 or something. for example if your origional pinon has a +2 and has a .025 shim and the new one has a - 3 you want to put in a .020 shim, i may be backward with that, it may be .030 i cant remember. well anyway if it whines alittle its no big deal if the noise dosnt bother you, a friend of mine put his bearing on without a shim, i told him it gonna be louder than hell and may not hold up. 2 years later hes still running on it making a bad wine at 40mph.