Hey all, My rear, a 9 inch, only has 300 gears in it. It came from a 65 T-bird. I know that 9 inchers can be changed out quickly, but I dodn't want to go 5-700 bucks for an entire pumpkin. I see ring and pinions for 180- 250. I have been told by many that a rear setup is somehing very critical; but I figure if I can make my own frame, and yada yada, then I should be able to... What do you all know about the difficulty o fplacin in gears. I wanna go 456 or 488s. I had a chevelle in highschool with 88s, and it was outta control, literally. Pork
In our area (baltimore) we have some u-pull-it junk yards that sell whole rears for 75 dollars. Some of the 70's-80's Ford trucks had the 9 inch rears with some nice low gears. They usually have a tag attached to the pumpkin that can be deciphered to tell you what gears it has. This may be a cheaper and easier alternative for you. Just pull the axles and drop the whole pumpkin out.
I agree with the junkyard pumpkin idea for the cheap way out. About the lowest ratio you're likely to find is 4.10 if you check trucks but 4.56 & 4.88 are a bit much unless you don't ever plan on driving it anywhere except around town. Check to see if you have 28 or 31 spline axles as well.
A lot of the yards around here don't see too many 9 inchers anymore. It seems that the supply has finally started to dry up. Not a good thing!!! If ya can't find any in your neck of the woods....my buddie has a few and may be interested in gettin' rid of them!!! Drop me a PM!!!!
Much data you will need is available on line. You will need some specialized tools. I use a ford ch***is shop manual as it is very comprehehensive. Expect aftermarket ring and pinions to be noiser than stock. Count on rebuilding the unit when you change r&p. The shop manual will show you how to decifer the tag i.d. 4.88s totaly rock,have fun!:d
There are different carrier (the chunk that the ring gear is bolted to) sizes, they are refered to as a 'series'. Your rear has a '3 series' carrier, what that means is that it will accept ring gear ratios in the 3's (ie 3.56; 3.77 etcetc) i believe here is a special cut 4.10 gear for the 3 series carriers but that is as low as that carrier can handle. To get to a 4.56 or a 4.88 you'll need a 4 series carrier. You might have good luck with a 4 wheel drive rear, like a bronco or pickup they would probably have a good ratio as well as positraction. Good luck, oj
set-up for a '9' is pretty straight-forward,it can be done on the tailgate or on the ground at the racetrack with minimal tools.if you have a workbench,vice ,and someone to hold your beer and cheer you on you are half way there. always ck the contact pattern in a couple places before instlation,it also helps if you can "feel' the pre-load on the pinion and can judge a few thousants back-lash. if you can't, borrow a inch lb torque wrench and a dial indicator it is one of the eaiser styles to set-up. grab a book or do a search,follow the directions,if you hit a snag PM me it aint that hard
Hold on, didn't the t-birds have a larger ring gear? I have one out back I pulled from a '65 convert and it is NOT a 9" I think they are a 9.75" or something similar. They look like a 9" but are much larger.
Things I have found from experience: 1. In 9 out of 10 times, the original pinion depth shim will work for the new gears also. 2. ALWAYS wet-stone the back of the new gears and carrier flange to check for high spots. 3. The pinion bearing preload is always tighter than you think it should be. It should turn hard with one hand and never be able to spin it. New bearings wear in and get looser. 4. In drag race applications, set the pinion depth a little deeper than normal to compensate for case deflection so the pinion is centered under full throttle. 5. Never set the ring/pinion backlash too tight. Set it 1/3 from the loose end of the range to allow good oiling. (After about 300+ sets to my credit)
all you need is a torque wrench in inch/pounds to test preload and a dial indicator for back lash. yes they can be set-up on a tail-gate with no special tools been there done that but you need experience to know when it's close
Good thought Cliffy, some lincolns, big mercurys' and thunderbirds came with a 9 3/8" rear. The housing is the same as a 9", the ring gear is larger, nothing interchanges and i'm told there are no gear sets available. Too bad, they are bullet-proof too with 3.25 carrier bearings you could go all the way to 40 spline axles and the case is probably as strong as a nodular piece. A way to tell is that the pinion support is larger and has a different bolt pattern, lay a regular shim on top and see if the bolt pattern matches up.
the 9 3/8 pumpkin will fit a reg 9'' housing. you can grind a small spot on the top and bottom or you can turn it 90 degrees and it will fit. Its heavy work with the fingertips.lots of them come with a posi.
Yep , the salvage yards are full of Ford trucks & vans ! That is the cheapest way to go . Might be just as cheap to buy the complete rear but just ask for the price of the 3rd member first , the for the complete rear . Look for a 4x4 pick up and you can get a posi rear from them . Have fun ! RetroJim
Gears in a 9" are the easiest to change (you don't have to do it under the car) if set up properly (even with new aftermarket gears) they shouldn't make any noise, unless you set up your gears wrong, or use worn or bad bearings.
Not trying to hijack here, but if the op is going to work on 9's he/I may need to know. What if your center section has 28 splines and your already installed rear has 31's? Is this a simple change?
One thing to keep in mind with the Ford truck 9 inch. Most mid 1973 on back are 28 spline and mid 1973 on up are 31 spline. I have found 3:73 and 4:11 in truck rears.
No such things on 9" rear ends, anything from 2.47-6.50 and up ratios will bolt to the same carrier. The different carriers are for 10 and 12 bolt Chevys.
3:50 is a fairly common ratio for ford pu/bronco. Look for 1/2ton ext cabs for 4:11's especially the 4x4s. Or just grab a center section and set it up with the gear you want. Its not too difficult to set up a new gear.
How do you set up the carrier preload so that the crown gear doesn't deflect and put the tooth pattern out of line, thus killing the gears? Just winding in the side adjusters will give you your pattern, but they must be tightened against each other to prevent deflection as the load comes on. Whats the spec on that??? Ft/lbs...1/2 turn per....????? Changing the side gears will require full dis***embly of the carrier and resetting this preload. Also, I've heard some carriers are too small in bore to accept the 31 spline axles without machining, but I haven't crossed that bridge myself so I don't know for sure.
Drive Em is right. 9's don't have carrier differences, like the GM stuff. 2.50 to 6.50 on the same carrier.
preload is checked at the pinion same as the pinion preload only it's 55inch pounds rotate the ***embly a half a dozen rotations to make sure everything is seated before you check the caps have to be torqued to spec for the preload and back-lash to be valid.
There are supposedly a few pre 73 trucks with the 31 spline, depending on the motor and options. 6 cylinder pickups usually have 3.73 and higher gears. Or if the truck has an overdrive, the gear is usually steep as well.
School up and tool up. It won't cost much. We need more people that can do this for our peers, and themselves. It is not that hard! Even I can do it!
I had planned to build my own 9" center section because I had never done it so got a good DVD off of EBay, a few special tools, a Nodular case, a new 3.50:1 ring and pinion and an overhaul kit. Still have everything but also ran across a newly rebuilt 3.50 Trac Lok so got it as well. My guess is the already built unit will get installed.
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