model a, ford 8", geared 3:00 ford 3speed ******...on the highway at like 60 its BARELY in 3rd. Id like to regear it a little. any suggestions for what to regear to? I've never swaped out rear gears before, whats involved? can i handle it myself? what parts should I be looking for? also, ive developed a pretty significant leak coming from my bellhousing/clutch area....whats the first thing to check for? I figure if im going to do the rear i might as well take care of this as well. -Rob
On an 8" ford you can change the whle chunk - or change the gears in your chunk. I rebuilt my 8" chunk with 3:73 gears I got from summit (180$) along with a rebuild kit/installation kit that has all the gaskets, crush sleeve, bearings (100$)and it was not all that difficult reading directions I got off the internet. Prices are a complete guess - I can't remember exactly That was an open rear - do you want posi? You can buy rebuilt 8" chunks with posi of ebay for like 600 with what ever gear ratio you want. Then it is just a matter of changing chunks - you pull the backing plates slide the axles out 2" then undo the bolts around the chunk and wa la. On gear ratio - what diameter tires do you have? What rpm are you running at 60 barley in third? find a gear ratio calculator and put in your tire diamter and figure what rpm you want to turn at what speed - I think a 3.80 gear would be in order - maybe a 3.55- or what ever they have close to that in 8" gears. Your ****** leak could be your rear main seal or the shaft seal on the ****** - what motor ****** are you running?
I started looking into this myself a couple months back. I never got around to it (somebody stole my replacement rear end), but this article over at Pirate 4x4 answered a LOT of my questions and made it seem a lot more doable. I still have a lot of questions, of course, but that gave me a pretty good place to start.
that is an excellent article, thanks for the link- the boys with the crush sleeve thread should read that too.
thanks, ill look into it, its a posi yeah. i keep hearing the local speedshop with swap it out for around 3-400...id like to do it myself to learn, but if its going to run more in tools.time.money...
posted pics of the tires, dont know exactly how tall. as for RPM i think im at like 2000-2100 rpm at 60 in third. maybe less. motor is ford 302 ****** is a 68 mustang 3 speed.
You can do most of the work yourself... I would go ahead and get evrything most of the way done, and find a good shop to set the final backlash on the gears, and make sure the crush sleve is properly crushed.... If you find the right shop, they might even let you watch so you can see how they do it..... You could probably get away with doing it all yourself, but blowing up your rear is kind of a steep learning curve. Then next time, you will be able to do it yourself....
Log on to the Kentucky Differential web site. The guy knows all there is about 8 and 9" Ford rear ends. Odds are with the kind of RPM your talking about, it's probably a 2:79 or 3:00 and I would bet my next paycheck, that it is not a posi. If it is, you have a needle in the haystack. I have 2 Ford 8" posis, a 3:55 and a 4:11, I looked at 1000s of junk yard rear end ***emblies over a period of 20 some years to find these............they are rare! The guys at Kentucky Differential are re-poping them and Auburn gear still has a few in stock, but they are not cheap. I used my 3:50 gear for a while, it's a good all around gear, anything much lower is great for performance but unless you have an overdrive transmission, I'd p***, as they are horrible on the highway. My ride is a 40 Ford coupe, healthy 355 SBC with a 350 trans. I'm definitely still a performance nut, but I found with a fairly light car, unless your going to race it, the 3:00 works very well. I'm sure there are a thousand oposing opinions. I had the 4:11s in for a while and added dual quads, excellent idea with gas prices the way they are!!!!!!!!!!!!
On the leak, you should be able to tell the difference between engine oil and trans lube by feeling it. Older formulations of trans lube also have a...ummm...distinctive fish smell; probably synthetics don't. Also, if the bellhousing has a removable bottom cover, you might be able to actually see where the leak is coming from, unless it has become involved with the flywheel and distributed all over everything.
thanks, its the ****** leakin, as the oil level not going down no removable cover unfortunately. im going to take it to the speed shop in my town and see what they say, hes been recomended specifically for rears.
Tudor, lots of great info but not 100% of story.It would take a book for all info on all rears and situations.I still learn everyday.
yup - it's missing some stuff - I may have missed it but I don't think I saw any crush sleeve mentioned - but it is one of the better ones I have read. When I did my differential - I had a thousand questions when I was going through it - stuff I just had to make ***umptions about because only the school of hard knocks can really teach you it all. I just hope what I did works!!!! I tried to follow all the rules I could find. But I picked up an extra third member at a swap meet the guy said worked fine when he took it out - best 20$ back up plan I figured I was going to find . I can't wait to find out if it works or not!!! Are you still hauling *** with that flat head??? I know you know what your doing!!!
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