Changing rear end questions

How does one go about changing their rear end, or gear ratio, or whatever you want to call it.

What is this process?

What kind of parts, model etc. Would I try to find?

How much does it cost?

Does it affect other things also and has to be changed?

I need to get better gas mileage than this?

Someone help please!

My 1967 Chevy Van gets horrible gas mileage I had no idea!

B

Like I said, it depends on if the odometer is correct, what transmission is in the van,,,,what driven gear is on the speedometer cable,,,,,what tires you have,,,,and what rear end gear ratio you have,,,,,11 MPG could be normal depending on how and where you drive and if you have a Carter YF carburetor with problems....you have not answered ANY of OUR questions....so we cant answer yours....

what engine? what gear do you have already? auto or standard?
I have a 230, 3 speed standard, 3.73 rear end, and a monojet carb. I get above 17 mpg's.

Thanks , I am not a mechanic, sorry can't answer much questions about that.

The engine is 6 cylinder, I don't know more than that because the mechanic here in town changed the starter, and said he got 3 different ones, and none fit, so he put in a celenoid instead???

The carberator? Looks clean, small??

These are small tires, nothing changed original.

The rear end? Someone told me about bolt counts, I forgot what it was, whatever it was I remember mine came to " bad ratio bad gas mileage" I remember.

So now, I am just trying to find others who changed the rear end, with what kind of "other rear end"? What COULD ( estimate) be the costs?

And does that cause problems for other things mechanical?

The van runs fine and smooth, no smoke, as I said, it seems fine, but mileage is atrocious and no I don't think the gauge is off, I drove it today and it seems accurate to what the mileage is suppose to be.

I hope this is enough. I would like to know if someone else has changed their rear end.

B.

I think you need to follow someone or drive another vehicle out 10 miles, then do the same in your van and see if the odometer goes up 10 miles,,,,it might actually show you are driving more miles than what shows on the odometer,,,,,,,and,,,,,,put down where in Kansas you are so we can see if anyone here is close to you,,,,,,we like to know where our fellow vanners are.....

if you can`t identify your carb or rear axle, take a picture and
post it, as far as the axle ratio, well you can count the teeth on
the ring and pinion gears or mark the drive shaft and the tire
have some one roll the van very slowly and count how many times
the driveshaft rotates to the tire`s 1 rotation and that will give you
a close idea of the ratio of the ring and pinion.
if the driveshaft turns 3 and 1/4 turns then you will have a 3.36 if it
turns 3 and 3/4 then you have a 3.73 if it turns a little more than 4
then you have a 4.11. hope this makes sense.
and again where in the flat state of Kansas do you call home?

I have either a 196 or 230 in my '65. Roared down the highway and found when I removed the rear cover several teeth missing and removed. Am not skilled enough to set up the new gears so had a shop do it for me--just left the rear and parts with them. I paid way too much (such work is really expensive in the DC area) and put in an already broken in .308 rear gear set. Guy (Brian) set it up for highway travel and he did a great job. Might be the quietest rear end I've ever had and one really needs quiet in a van as it makes a sound chamber. I have pretty big 15 in tires on the rear and she runs down the highway 70ish nice an quiet--both the engine and the rear. Probably good if you are on the flat side of Kansas.

So, in other words, IF you have a pretty much stock van with the typical oversized tires we put on them a .308 rear is great on the highway and I can still get going in 1st. Not as much pick up in 1st as it used to be tho but everything is a trade off, eh?

To anwer your question, our Chevy rears are about the most common on the road for about 60 years so if you find any competant shop or machine shop that sets up gears you should be able to get something done for under $500. And, used gears are fine if they look okay and the are lapped properly. Our carriers (the thing the whole assembly lives in) are wider than most so it makes it a little difficult to find one same width. However, welding on spring and shock mounts is a piece of cake for any shop you might look around for a used rear--especially if you are running fairly wide mags. Also you might find some threads on hear aboot interchanability of different rears.

Good luck and happy motoring, Mark