Hey Folks,

hope you're having a better Memorial Day weekend than I am, in preperation for getting the dual exhaust kit next week, I spent all Saturday trying to remove the exhaust manafold bolts and clean and antiseize them and re-instlall, which went perfect!

Then I went for the test drive, just wanted to take a spin it was a beautiful day.

about 3miles from home I get the usual vibrations I've been experiencing and thought that it was my front wheel bearings which I repacked and it did seem to change the vibrations occurance, from 45ish to 55ish when I noticed.

Well, in 2 seconds, bout the time I got up to 55mph BANG I thought I blew the engine, but noticed parts flying out the back.

I lost the drive shaft, and the last 4 inches of the tailshaft of the transmission (I think it's called the tailshaft, it's the part the yoke slips onto).


found this on the side of the road bout 1/2 mile back


Luckily found the drive shaft & yoke still in 1 peice and not wedged thru somebodys windshield!

This could have been worse, Thank GOD no-one was passing me at the time.

Ok Decision time here and I'd like to ask Yall's advise....

1: fix or replace the ol' 3speed and rock on?
1a: can you even get parts to rebuild these 3speeds?
2: change transmission to somthing else? T5-5speed, old 4speed etc?
3: change out entire drive line to somthing else?
I have a donor 71 Mustang with a 302 c4auto w/ 9in rear (that someone wrecked for me back in the 80's.
4: is there a "list of" transmissions that will fit the flathead 239 V8 with a kit or adaptor?

Personally, i'd like to keep the Flathead going as long as possible, but have pondered a 289/302 or 351 with auto trans.

I may have access to a few late 80's early 90's Ford trucks with 4 or 5speed transmissions, Not sure they would work, but probably free parts for me there courtsey of my brother.

I know there are lots of posible paths here, looking for one with a easy price tag that could keep the Flathead or without too much cost, but if changing the entire drive line is worth the cost I'm interested in suggestions (no GM engine suggestions PLEASE, no blastpheming in here!).
Transmissions I may can let slide!

Thanks for any suggestions and Thank God again no-one got hurt,
cept for my truck.

PS: 2 restored Cheap Heaps Every Val Rattles Oil Leaks Entire Times drove by me and didn't even stop!
Had 2 offers to sell it waiting on the tow man.....what is is world coming to???
T

 

Anxious to find out what you learn. Will be subscribing as this has interest for me as well.

 

hey 19fifty4, I been doing a bit of searching since posting this morning,
found a link:

https://www.ford-trucks.com/forums/1...s-how-tos.html

It's got some very good information here but....

I'd still like to hear it from the folks "who've been there, done that'.

I surely hate to think I'll be selling this truck only 6months into trying to bring it back alive! Let's not go there yet.

T

 

How did it come off the differential? Is the drivetrain completely stock? Something must have bound up really hard for that to happen. The part of the tailshaft that broke should be a couple of inches inside the tailhousing, I'm just not seeing how the driveshaft could come out of that. Did it destroy the tailhousing?

 

Good point Ross...sounds like the problem may have started at the rear and the damage at the front resulted from the driveshaft flailing around.

 

I'll just say i love driving my truck a lot more with the c4 conversion with the 9in with 3.0 gears it can sit at 65 all day with no problems and gets about 18mpg. its not gonna beat anything off the line with that gearing

 

Check out Van Pelt Sales to see about getting a tailshaft replacement (and bearings and seals since it'll be all torn apart anyway) or look into doing a T5 tranny swap.

Amazing it snapped like that.

 

Ross, good question. IMHO the vibration was caused by a failing rear U-joint. When the joint finally failed completely, the whipping driveshaft stressed the tailshaft and snapped it off. I'd examine the rear U-joint if it's still around and the U bolts that attached the joint to the rear end. The joint may have failed from lack of lube, incorrect pinion angle, or possibly too long a driveshaft if the rear axle had been replaced. Had the tailshaft failed first, the truck would have acted like the tranny was suddenly shifted into neutral, and just stopped, would not throw parts out.

 

Did you switch the rear end to a 9 inch at some point? If you did and kept the stock drive shaft, then only about 2 inches of the tailshaft splines were engaged (and little or no rear bearing support). Those trans have a very short yoke,and the 9 inch has a shorter pinion making matters worse. I used a longer yoke which helped but still had a vibration.
I have since swapped to a 5 speed which works great. I still have the old 3 speed if you want it....

 

Hey Guys,

Thanks for the info, after mulling this one over and discussing with my brother,(& Like Axracer said) he said pretty much the same thing, sounds like a u joint failure.

The U joints, I had pumped them up with grease about a week before, first thing dad says is I probably put too much grease in them!

you all mentioned is the drivetrain stock, best guess is (not sure)it's the way it was when I got the truck, it all appears to be stock; I do have a 8ba engine, but trans back not sure I'd say yes but could be wrong.
I found some photos of "rears' I "THINK" I have a Dana Spicer rear but that's my best guess. I can post a photo later.

Sorry if I rattled on in the first post, no 71 Mustang drivetrain installed YET, I was wondering if it would fit (Since I have one to use) and found info stating that the 71 Stang 9in rear was suposed to be a good fit on these trucks.

Hey Tinman, Thanks for the offer, depending on how this goes I may need to get with you on that. Thanks!

Also; there appears to be 2 sources i found on parts or rebuild so far.
Little Dearborn seems to actually sell the transmision parts I may need and
a business called "Joe Smith early ford and hotrod" in Glen Allen va which is pretty much backyard local for me (found on Ebay) rebuilds and sells transmissions.

you know the dern thing that fooled me, the front wheel bearings had a vibration I felt, (due to needing repacking and tightning up) I did that, the vibraiton I was feeling around 45 went up to 55mph, but that was probably when I put grease in the ujoints too, it may have very well been the ujoints the hole time. Even pushing in the clutch or going to nutral I still had the vibration, could feel in steering wheel but after wheel bearing repacking it lessened.
Also I noticed upon shifting in 2nd or 3rd id get a vibration on accelleration,(intermittantly) & sometimes engaging the clutch and letting it out again it would go away, or not be as bad. More sighns of ujoints?

I would guess if it was the transmisison the whole time the vibration would be constant, but who knows.....


Well, now I know.

I'll keep yall in the loop on how this goes, hopefully a repair can happen before I replace.

PS: IF I were to go with a transmission adaptor (Like from SPEEDWAY AUTO) any suggestions there? I looked at them, you can run a Muncie 4 speed, or a T5 5speed etc,

What's the best fit transmission if i were to go that route?

My brother has a few 87-88-89 &90 wreked ford trucks with 4 or 5 speed manuals, shame I cant use one of those.

T

 

Thanks Havi Will look at them (Van pelt) too!
Tom

 

Sorry to hear of your mishap, that had to get your adrenaline pumping!!

I have a 3 speed tranny out of a '53, that I won't be using, not sure how I'd get it to you? If you were going to Doc's Truckstock I could bring it with me.

 

Doublecanister,

I don't want to set off a debate here about Pure-Restoration vs. Resto-Mod vs. Street-Rod vs. Darkside. In my opinion, these are all legitimate expressions of the sport I call "old-trucking".

My truck has a drive-train very similar to the one you have in that Mustang donor, and I can tell you that it is a pleasure to drive. I drove it 200 miles each way to the SuperNat's last weekend with no problems and it got about 20mpg with the AC running and the headlights on high beam.

If you're going to be driving it much, it's nice to have a later model drive-train with power steering and disc brakes. Yes, I realize that I'm spoiled rotten but as the great philosopher Joe Walsh once said, "They say I'm lazy but it takes all my time".

-DV

 

Hey Doraville, Thanks for the information that's good to know, It would be nice to be able to use the truck like that (fairly long trips with AC ) heck yeah!

This truck is like the Mustang I restored, at this point I can go so many directions it's unreal, Unfortunatly the "Wallet" is the compass here!
never thought the Wallet could point a direction till I started doing this stuf!

Hey, if you dont mind, PM Me what you used for a drivetrain.
any specifics would be nice, again if it's not too much trouble, Iv'e never had a vehicle like this before with so many drive train possiblitiys.

Thanks!

T

 

Here is my build thread. It's almost identical to your Mustang except I have a C6 in stead of a C4. I did that because "back in the day" the C4 had a reputation for being rather weak and the C6 had a reputation for being indestructible. I'm sure that with the right transmission man and rebuild kit the C4 would be fine. All automatic transmissions have some weakness (except for maybe the Allison in my diesel PU), and over time the kit suppliers incorporate fixes and upgrades to overcome the weaknesses. Maybe some of the folks here who have more knowledge about the C4 can chime in and tell us the details.

One drawback to using an older 3-speed automatic is that you'll want to use a higher rear-end ratio (I'm sure that the one in that Mustang is fine). I had to switch from a 3.78 to 2.80 to get the kind of cruising speed that I wanted (I think that I run about 2500 rpm or so at 70mph).

-DV