got a 98.5 w 24v dually. i pull a 34 ft. fithwheel camper. i up sized the tires and now the truck is slugish pulling trailer the truck has 3.55 gears and i would like to go with 4.10s any opions. and also would like truck to stop better. any one know of disc brake conversion kits for rear or whats this upgrade to gm wheel cylinders.also what rear end is it, dana 60,70,or 80 how can i tell thanks alot for any help

 

The rear wheel clyinder upgrade is simple & cheap. About $30 is all. Just go to a parts store and tell them you want GM wheel cylinders for a "99" GM. They are all the same. Just replace the cylinder (no need to remove the shoes) bleed and go....I mean stop.

Actually, it might be a good time to do a rear brake job and replace the shoes and turn the drums, clean up the adjuster, ect. More times than not the shoes are oil soaked and may grab under the new pressure. If you haven't done them on a 98.5 it's time. I had to redo mine.

Hold onto your coffee.

 

tell them 1 ton or 3/4 ton GM ?
or does it matter?

 

The GM rear wheel clyinder upgrade is good advice. I did mine last summer and noticed a great improvement, another bit of advice is to adjust the rears yourself, and flush out your old brake fluid with some new stuff. From what I'm hearing and reading upgading to Disc's is not worth the price and the Manufactures are going back to the drum style braking system JMO. Good Luck

 

I think the 3500 (even with the auto) has an 80. I went from 4.10 to 3.54. If you don't want to add power to make-up for the tires gearing isn't too bad on a 2wd. (BTW, I have two LSD carriers and a 4.10 gear set doing nothing).

I agree the disc conversion is probably not worth the cost. I have not done the wheel cylinder upgrade yet but it isin the plan for both trucks.

Randy

 

4.10's are awsome. So are discs, easy to change pads etc.

 

Don't tell them what the larger cylinders are going on or what they are supposed to go on. The Napa #4637337 will cross over at any auto parts store is exactly what you need and is all the information they need.
Any more info just confuses them and you will likely end up with the wrong part.