3.55 gears???

[DriverSideImpact98]

I have the potential to get very slightly used 3.55 gears out of a CV.
How difficult is it to install 3.55 gears into my currently 2.73 axle? Is there a lot of adjusting, shimming, backlash, gear mesh stuff to worry about? Or is it really straightforward: Unbolt the old, bolt in the new, and drive away?

[pantera77]

I have the potential to get very slightly used 3.55 gears out of a CV.
How difficult is it to install 3.55 gears into my currently 2.73 axle? Is there a lot of adjusting, shimming, backlash, gear mesh stuff to worry about? Or is it really straightforward: Unbolt the old, bolt in the new, and drive away?

It's the first one unfortunately.

But, 3.55's are awesome. Now would be a great time to add a trac-lok too.

[hypostang]

I recommend professional installation , the things you mentioned all need to be addressed

[1980c10]

Yup it's a pretty involved project. If your not extremly comfotable measuring, shimming, seting backlash and such. Have a professional do it.

[DriverSideImpact98]

I figured. I am not entirely comfortable with all that shiz. Last time set up ring and pinion stuff was on an International S1700 several years ago.
The guy wants $125 for the set. The 3.55's are almost a must have though. Towing my boat with 2.73's isn't working it.

Whatelse do I need to know about swapping gears? Other things I need to do? Etc.

[cld783]

Or is it really straightforward: Unbolt the old, bolt in the new, and drive away?

if you swap the whole rear axle it is..

[DriverSideImpact98]

Yeah. the issue there is that I have the air ride... Granted I'd be fine with springs too...

Anyone go that route? Adding or taking away the air springs?

[DriverSideImpact98]

Actually...that brings up a whole new situation. I just noticed my right drivers rear side is sagging like a mofo. Not really surprised being that my GM is a 98...and its a Wisconsin car. So whats the best route to go? What is the cheapest route? Just replace the air springs? Or convert it to regular springs?

[gadget73]

there is only one height sensor on those. It can be off-level left to right and still satisfy the sensor. Put a jack under the frame on the side thats low, and pick it up some. The air suspension will vent, but more air will come out of the side thats not supported. REmove the jack and see if its more level.

[Smokestacklightnin]

I suggest a good reputable shop to do a rear gear job. It may get rather expensive also. A shop not too far from me does nothing but rear ends, from stock replacements to all out race set ups. If i provided the parts i would be looking at about $800 in labor, but this shop is one of the best. Needless to say i'm putting it off.

[DriverSideImpact98]

Anyone ever hear of these guys? Anyone have first hand experience? Not a bad price at all.

http://www.strutmasters.com/mercury-grand-marquis-suspension-s/65.htm

If I were NOT to get a conversion kit and wanted to do it myself (I'd like a little taller/stiffer/heavy duty ride in the back), what would I all need to do to convert it from air to coil??

[Leafsrule16]

Just hit up a junk yard and grab two coils. Its easy as hell to do but if your air ride is fine id keep it. Auto level is nice and it rides so smooth

[DriverSideImpact98]

It did seem a little better this morning, but the ride height is not equal. I do like the auto level, it is convenient and a smooth ride. But I was underneath it today and I happened to check out the bags and they are kinda rough looking, starting to dry crack pretty bad.

Anyone know what the replacement air bags go for or a good place to get them from for that matter?

[DriverSideImpact98]

Just hit up a junk yard and grab two coils. Its easy as hell to do but if your air ride is fine id keep it. Auto level is nice and it rides so smooth

I think I'm gonna have to swap in springs. My compressor sounds like a lawnmower. It's probably burning itself out by keeping that air bag filled up.


Is it really that easy to swap in coil springs in place of the air bags?


Also are there springs from other models or years (other than 92-10 Aeros/Whales) that will fit on a 98 MGM?? I'd like something stiffer/more heavy duty. Or is there a good place to get better springs from?

[Shewey]

Air to Coil

I swapped out the air bags for coils on my 2000. Quite simple but I did also change shocks because of different damping rates. There is a wire in the harness behind the glove box (blue I think) that will kill the "Check Air Suspension" light on the dash. Just cut it.