If your rear end is sound, and you're already thinking about a trans swap, keeping the existing rear end gears and using an overdrive transmission is another option to consider. A 3.90 with a 30% OD (0.7) would give you the equivalent of a 2.73 -- a nice "highway" gear set; and also keep the acceleration and fun characteristics of the 3.90. (I'm planning a similar route; but with a 4.11 rear and 200 4r automatic OD.) Upgrading to an OD shouldn't be too much more than rebuilding the rear, and gives the best of both worlds...
Tires... They Factor Into The Driveline Ratio Too! Hey Steve you really need to include tire diameter into the equation of what rear axle ratio works best. I have 3.73 gears in my truck, but I also have 31" diameter tires. So what? Well I have to slip the clutch a bit to get it moving due to the "launch ratio". The gearing and tire size though on my truck is great though for gas mileage. I'm a manual trans. guy and plan to install a heavier flywheel, which will help in my case.... but I digress, enough about my ole crate..... I'd suggest you use a ratio calculator, plug in all your data into it and see where you are. Here's a calculator for ya: http://www.4lo.com/calc/geartable.php Lots of other good calculators and data on the 4lo.com site too! Launch Ratio: More information on that can be found here: http://www.5speedtransmissions.com/startlineratio.html Hope this helps! John
It's definitely NOT a Ford 9 inch and looks to maybe be a 55-64 Chevy car rear. The 9 inch has the pinion and pinion bearing mounted in a saparate case that bolts to the main housing with five 3/8-16 bolts. You can find a PICKUP 9" that is too wide and send the housing and axles to Moser Engineering in Portland, Indiana who will narrow the housing, shorten and respline the axles, and redrill to a six lug pattern. The pickup has a 5 0n 5.5 bolt circle so the flange is wide enough for the 6 on 5.5 pattern. This is a bit pricey after throwing in a ring and pinion of your choice plus an installation kit---grand total $600 but it's a guarenteed exact fit. The earlier Colorado/Canyon with the drum brakes would have the six bolt pattern and be cheaper. We have been using the Explorer 8.8" rear a lot lately because they're the right width for many of the older cars/trucks, come in 3.73 ratio (2.61 final in overdrive), have a great emergency brake set up, are limited slip, and hold up under the 1500hp twin turbo Mustangs. The drawback is the axle flange is designed for the 4.5 inch bolt circle which can be re-drilled for the 4.75 on five or the 5 on five (close), but not the 5 or 6 on a 5.5 pattern.
Whew And there you have your final answer Steve ; From folks far more experianced than I no less . FWIW , I rather like the 3.90 ratio as it's a good mix of power to cruising speeds for older rigs . Also , as the numbers go down , the ratio goes higher and vice versa .
One step at a time Man....you guys sure no how to overwhelm a guy with info. All joking aside, thanks for all the info here. It has been amazing. If nothing else I have realized that there are many factors to be considered. The good news is that it seems I can keep the rear end that I currently have and the gear set if I make some corresponding choices in other areas. I think I do need to tackle this one step at a time though so the first thing I think I need to do is the following: 1. Measure this rear end to make sure it is the correct width. It was on the truck when I bought it and I didn't think it looked "wrong" on the truck but I wasn't really paying attention to that before I tore it apart. Is there a width that it should be and what is that dimension measured from? Is it hub to hub or what I call back of disk to back of disk? Does anyone have that info? 2. Since I have removed the pumpkin, taken off the yolk and front nuts, and the passenger side seal was/is leaking, can I pull this rear end completely apart (removing all parts) so it can be powder coated with the frame? Or will that mess up the guy who is rebuilding it? If we start with just those 2 questions, that will give me something to work on this weekend.
Evan - Do these pictures help to determine what kind of rear end it is? I thought I would give some more close up pics of the rear end to see if anyone would know by some of the features what type it is. Also I was wondering if this bracket (below) can be removed. It served no purpose when the truck was put together. It would be nice to clean things up that aren't needed. And there is something like a small vent tube next to the bracket. I assume this needs to be kept in use. It has the markings S W on the cap: http://www.flickr.com/photos/106654228@N03/10487197676/in/photostream/lightbox/ All I could do is post the link to the 5 pictures on Flicker. If anyone could tell me how to insert the pics into the actual posting that would be helpful too
All I could do is post the link to the 5 pictures on Flicker. If anyone could tell me how to insert the pics into the actual posting that would be helpful too [/QUOTE] When you go to comment, scroll down there are additional options below. Click on manage attachments, and you can upload your pics there.
Steve, the bracket seems to be where the flex brake line mounts to the splitter that allows you to run a line to each wheel cylinder. You will need something like that, so I wouldn't cut it off just yet. You might want to move it, just depends on how you are doing your plumbing, but if it was all hooked up originally, it should be fine to leave as is.
If anyone can help with these 2 questions.... If anyone could help with the 2 questions above, I would greatly appreciate it...
Steve, the width should be 62" from mounting surface to mounting surface if you are looking for stock width. Mounting surface is the face of your drum where the lug bolts come through. Hope that helps with question #1. As far as Question #2, if it was put together, it will come apart. You just might need some extra tool to do it, I'm not sure. Couldn't you just paint it with Rustoleum or that other epoxy system others have used. (P-15, or something like that~) ?
I measured it up and it is good news.... Paul - I measured it tonight and it is pretty close to 62" - give or take a half inch so that is good news. I think I will just end up using this existing one. Also picked up the engine today and found the name of a good rear end shop locally here so I am going to take it to them and see what they would charge to pull apart and rebuild. I would like to powder coat the rear end in conjunction with the frame I am just not sure if it is advisable or if it will create problems????
Powder Coating If they get any coating on the sealing surfaces , it'll be *very* hard to make it not leak / weep . I'd go for a professional paint shop re - spray , gloss black . Actually , I work and drive my old truck hard so I just use Rustoleum or Caterpillar gloss black paint in the handy Foo-Foo Can .
Nate - I may try painting it myself... If you don't think powder coating is the way to do, I think I make paint it myself. My next project will be my own make shift paint booth built out of PVC, plastic, and some fans.
Home Painting ! Yes , YOU can do this making a paint booth out of frame and sheet plastic . I did it in my back yard , I'm a terrible painter so my buddy did the paint works , it came out nice .
