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Discussion Starter #1
Found the weakest link Friday showing off for a co-worker attempting a burn out. Wasn't on it hard and can't explain why the pumpkin / case cracked were it did, but planned on swapping gears in a yr, x-mas will just come sooner for me.

From what i've read so far there where three different 9" housings. Need to confirm what i have for ordering parts?

Plan on going with 31 spline axles. Anything i need to pay attention to when ordering? I just plan on measuring what i have and using that for measurement.

Gears AND style?? Not sure what gears to go with or the various types. Plan on finding another pumpkin to replace gears. I will need to use my vibration dampner or it will effect the length of my drive shaft (that is new).

1963 Galaxie ( mostly street car, BUT i drive aggresively)
Warmed over / rebuilt 390 : 355Hp
TKO600
I drive highway 20miles one way to work and hope to drive car across country some day, say 200 miles a day.
 

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Discussion Starter #3
FE,

Will admit this was the only thing i haven't taken apart while doing restoration, and the nice smelly black oil showed it. How do you "properly maintain" the rear end? even if i had done an oil change theres no reason the case broke were it did? I didn't even have the tack up to 3k when i dumped the clutch. At this point figured cold black top and street tires may have added to breakage?
 

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It appears the pinion support let go, not unusual. GOOGLE DAYTONA pinion support (and hardened case as that most likely went also). 31 SPL (hardened shafts) is a good idea when building a new assembly.
 

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:confused:

How about axle wrap-up? Do you have any traction control device(s) on it (bars - pinion snubber)?
 

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Pinion bearings and rear support bearing were shot. Any style pinion would have let go in this case. You likely were not aware (or didn't notice) and odd humming or clicking in the rear, signaling the bearings were toast. What happens is the bearings wear heavily (often due to condensation corrosion sitting a long time), then the pinion gear crawls down the ring gear, forcing the nose of the pinion gear hard-upwards on the bearings. It's like sticking a crowbar into a pipe and pulling sideways. At this point, either the main case breaks at the rear pinion support needle bearing, or the pinion housing lets go.

Bottom-line, it was the condition - not the type of parts - that caused failure. Replacement with the same type and strength parts would be fine if in fresh and well-adjusted condition. That said, if you want to upgrade to 31-spline and Daytona support, it won't hurt anything either. Whatever makes you giggle.

David

PS: Yes, you need to measure carefully and inspect the case for micro cracks or other damage, especially at the rear pinion support area. If in-doubt, have the case MagnaFluxed to dye-checked for cracks. Most cases in the early '60s were 3.06 carrier bearings, though the 2.89s were mixing-in by '64. You might want to consider just doing a full rebuild of a replacement 31-spline center-section, most commonly found in trucks and vans. It will have the basic parts you'll need at a minimal cost compared to piecing it together - unless you're changing the ring gear carrier anyway.
 

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It appears to be the original rear end??? 9" Fords are good...some better than others. Your housing is the first generation 'round' housing (the weakest but cleanest looking). The center section...much the same (the weakest). Not knowing your plans or budget...just fixing what you have, I would leave the housing and axles alone. 28 spline alxes should survive street tires and horsepower. It appears that the old ratio was around 3.00. Not a bad gear for going down the road but you do have a TKO600 with a road gear overdrive. I have the TKO600 with the road race fifth gear. I have 4.11 - 3.00 ratios. I used the 3.00 with TractionLoc when I did Hot Rod Power Tour and was satisfied with the road performance. If I had the tall overdrive, I would not have liked the 3.00 gear. I have pulled that 'pig' and installed one with 3.50 gears and a Detroit Locker. Very satisfied with the all round performance. Since you are looking for a used center section, at minimum, look for the two vertical support ribs. Get some kind of limited slip or locker. Rebuild with new bearings, Daytona pinion support, and shim the pinion support bearings. 427 Galaxies came with 3.50 gears and Detroit lockers. CJs come with 31 spline axles, Daytona supports, and shimmed support bearings. If your plans are to go with more HP and/or tires and the budget allows, go for the 31 spline setup. Other than the axles, the costs for new parts is very little different. If you are close, I can show you the differences.
 

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What happens is the bearings wear heavily (often due to condensation corrosion sitting a long time)

David
Good Point!

The fluid should be changed frequently and the vent asm should be inspected regularly to ascertain correct operation. The axle asm actually breathes.
 

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Discussion Starter #9
I have a carrier out of 79 Bronco i purchased yrs ago from Randys Ring and Pinion. I sold the bronco and it took 2yrs to get the carrier back (i'm hoping the owner didn't stiff me and swap it with another)

If i remember correctly the bronco was a 31 spline inner?

How can i confirm the carrier is for a 31 spline AND that it is the "posi" unit i purchased?
 

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What is the code on the center section? The WAR case are rumored to be a weak link. I've read that the material at the bearing support is thinner and prone to cracking.

Jet
 

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I have a carrier out of 79 Bronco i purchased yrs ago from Randys Ring and Pinion. I sold the bronco and it took 2yrs to get the carrier back (i'm hoping the owner didn't stiff me and swap it with another)

If i remember correctly the bronco was a 31 spline inner?

How can i confirm the carrier is for a 31 spline AND that it is the "posi" unit i purchased?

If you have an axle laying around 28 or 31 spline a test fit will answer that question, A trac-loc carrier looks like


An 'open' carrier looks more 'open', being able to see spider gears....

I would say a ratio of 3.50 and up to 4.11/10 would work well with the TKO....
 

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You have been given good advice already but, I will just add my thoughts. Bought a rear end out of an earlier '79? F-150 at a swap meet. Good heavy housing with the ring gear hump, but a standard single support grey iron case. Got it cut down and rebuilt for my '64 Galaxie XL 460 (about 475 horse), traction lok, 31 spline Mosier axles new 3.70 gears. It stood up to a few burn outs on the street, 4 burn out box burn outs and 3 passes at the strip. On the 4th pass I broke it. Tore it apart and both axle bearing supports broke right above the bolts. I'd say they had seen their best days and with the added stress I put on them they just broke. Everything else was just fine. If you're not going to have any more horsepower than you have a good standard case, only if it is 'good', would be OK and you don't need 31 spline axles if you have good 28 spline axles. I have a friend that races an '80 Tbird 460 over 500 horse with 28 spline Mosier axles 4.11 gears, never had a problem. To make sure you may want to try and find a nodular case since you need one anyway and be absolutely sure.
Do yourself a favor and have a professional rebuild it for you. The correct pinion to ring gear mesh are critical and .007 gap is what my rear end guy used and he is a professional. A complete new Strange or Curry third member is $1250 at Jegs. And they are almost unbreakable. So don't let a shop charge you too much.
Good luck :)

edit: My rear end guy said a Ford Traction Lok unit is as good as you can get for the street and occasional strip. You don't need a Detroit Locker.
 

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Good Point!

The fluid should be changed frequently and the vent asm should be inspected regularly to ascertain correct operation. The axle asm actually breathes.
True. In-fact, some FSMs state the rear axle needs to be exercised regularly during storage to prevent problems. Who does that on the old car sitting in the (garage, side yard, field)? Makes me wonder why there aren't more issues.
If i remember correctly the bronco was a 31 spline inner? How can i confirm the carrier is for a 31 spline AND that it is the "posi" unit i purchased?
31-spline is true only in later years. The early broncos had 28-spline. To ID the carrier as locking/non-locking/whatever, post a pic or three.
If you have an axle laying around 28 or 31 spline a test fit will answer that question, A trac-loc carrier looks like

An 'open' carrier looks more 'open', being able to see spider gears....
I would say a ratio of 3.50 and up to 4.11/10 would work well with the TKO....
Actually the opposite. That's an open (non-locking) carrier. The Trac-Lok has more thumb-sized holes (normally four) to allow a greater flow of lubricant to the clutches for cooling. Also, the wide cap at the top would be bulged-out with recessed bolt head pockets to make space for the clutch pack. The pic shows a flat bolt head area, also indicating an open carrier. I agree with the gear selection, as the tall highway gears and an OD will lug the engine out of its efficiency range and can actually reduce mileage.

David
 

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Thats what I get for believing E-Bay (swiped the pic ;) ) But that said, here's a fairly good info article on the Ford 9" And identifiers.
 

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lots of good info here..:tup:
 

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I'm running a 3.50 gear with a Trac Loc and it's been good for 13 or so years in my Falcon. I am running a modified C4 not a manual so I realize it's not the same. On the highway I'm wishing I had another gear for sure! I'm also running 28 spline Currie axles but ran stockers for ten years before I had the rearend narrowed a few years ago.

With street tires 28 spline axle should hold up for years. I won't say the same if you ever bolt on some slicks!

John
 

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On the subject of 28-31 spline axles this is the method I used for years to tell the difference, without physically taking an axle out. It works 99,9% of the time on the 'older' stuff.... Telling the difference between 28 spline/31spline axles....
 
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