Chevy & GMC Vans

I've had a few people ask my opinion of the 4:10's that were installed in my van a few weeks ago,so I thought I'd do up a quick summary.Keep in mind i'm running 215/75/R15 tires approx 27.5"

For my style of driving generally under 90kph (approx 56mph) and usually around 50kph (approx 30mph along backroads) the new gearing is working out great,I have a ton more get up and go from a stop and pullin the local hills is no longer any issue at all,there has been a slight reduction in mpg overall but not enough for me to worry about,I know there will be a huge increase in how it Tows my trailer as I've already tried this gearing in Deans old van.
My plan is for a slight lift and slightly larger tires come spring so the 4:10's may be reduced (in effect ) to 3:73's in the end, but this will still be better than my formally lethargic 3:42's

Now if I was someone who liked to drive at above average speeds say 140kph ( 87mph) (like what most folks are doing on the major hwys around here ) then I would definitley notice a drop in the mpg (and that would definitely need to be factored in)

I don't have a tach but I can sure as heck notice the increase in eng rpm's the few times I've needed to get up to those speeds and with a higher mileage eng like mine 310,000 KM's its probably better to keep it out of the upper stratosphere,lol.

So for those who travel fast on flat terrain and who rarely tow its probably better to stick with the 3:42's especially if mpg is your main concern,but if your driving situation is more like mine and you can snag a decent rear-end with the 4:10's already in there, then don't hesitate to grab them,you'll be much happier in your day to day driving.

Great write up zam. Definitely gives a heads up for those who are thinking of switching gears.

Good info Zam.

Personally, I never had an issue with my 3.42s. Even towing my sled trailer, they weren't bad. If a person doesn't tow a lot, I don't think you can beat them.

That being said, 4.10s are on my future upgrade list, but that will be after the 31's go on, and while I haven't done the math, I figure my effective gearing will fall back to the 3.42 to 3.73 range. Of course I'm counting on the V-8 to improve performance too!

I know this is an older post, but I need to get some more info if I can.

Can you tell me what you did to go to 4.10s?

I have a 1997 Safari and I want to go to 4.10s for towing.

I can get a 1987 axle from a slavage yard with 4.10s in it, but it is 10 years older axle and who knows what shape it is in from sitting in a salvage yard. Will that axle be a direct swap?

Or, can I order a "4.10 kit" from someplace and have a mechanic put it in?

Any help is appreciated.

An axle does'nt age just sitting around. I'd go that route ,cause buying new gears and having them put in is not cheap! ....somewhere between $750.00 and 1000.00 would be my guess.

dunedog wrote:An axle does'nt age just sitting around. I'd go that route ,cause buying new gears and having them put in is not cheap! ....somewhere between $750.00 and 1000.00 would be my guess.

Yeah, not cheap. That price range is a good guess. I can't speak for the 4:10's with stock 215's, but with my 255's they are great. Great throttle response off the line, and still cruise 80mph easily on the freeway.

Since the Axle is only $250 and is about a 2 hour drive in my Ford Ranger, I think I will go get it.

I may be able to unload my 97 axle to a junkyard and recoup my gas money

Thanks for the replies. I wont pay $750, that is too much for a '97.

afsigma, where are you located , i know of a rear with 4.10's for $100 but i'm in upstate NY .


in case anybody near me is interested .

http://albany.craigslist.org/pts/727103957.html

I know the add doesn't say what gear ratio it has but he's had it for sale for awhile for 250$ with no takers in another add that did have the ratio listed , i just can't find the old add.

afsigma21, the 87 axle is a weaker axle than your 97. The axle shafts are only 26 spline whereas your 97 is 28 spline. This is only a little weaker and should not be a problem. The leaf mounting pads are made slightly different as well. The axle will bolt up though and all you will have to do is widen the clamshell bracket a little so the bolt holes line up. I am not sure if the e-brake cables are the same or not. You can switch the brake backing plates and even all your brake hardware and drums over to the 87 axle. For $250 it sounds like a great upgrade!

I am in Ohio, so upstate NY is probably not realistic.

For me, the 4.10 is a must.

I am ditching my 01 Expedition because it is not comfortable to ride in and we loved our previous 2 Astro's.

My camper is 5000lbs, so I need to make every towing upgrade I can.

Should I even consider going to a 97 3.73? Those are readly available, but I assumed 4.10s would be far superior.

What say you!>!??

For towing your 5,000# camper, you will want the 4.10's! When you swap it in, fill the diff with synthetic fluid to handle the heat stress with towing. Also look into installing a tranny cooler. It is stickied in this section.

Tranny Cooler, Tranny Temp guage, Tach are all on the list.

I plan to flush the tranny, and replace all fluids I can with synthetic.

Anyone mount extra guages anyplace good?

afsigma21 wrote:Anyone mount extra guages anyplace good?

Here is a great location...

skippy wrote:afsigma, where are you located , i know of a rear with 4.10's for $100 but i'm in upstate NY .


in case anybody near me is interested .

http://albany.craigslist.org/pts/727103957.html

I know the add doesn't say what gear ratio it has but he's had it for sale for awhile for 250$ with no takers in another add that did have the ratio listed , i just can't find the old add.

Yeah,I'm interested! How far from you is he?
Of course I'll still need to swap gears for the front diff.But it's a start!
Thanks, Bill

From me , its about a half hours ride , less if you take the thruway .
contact the guy & if you need i'll go pick it & keep it here for you to pick up .