Blew out transmission maybe

[DB556]

Blew out transmission (yep blew it up)

Well I just got my plate and registration so it time to drive this deuce for the first time!, and I'm going down the road I shift into forth and pop and I cant shift well I'm grinding gears!
I think I must have not gotten it in gear, clutch etc I get over to the side of the road. This is loud maybe a Ujoint went. Its starting to rain so I hop
out and I look underneath and I have oil on the case, great! and I see the? Is it a tail shaft? or output bearing retainer? has broken and it floating on the output shaft.

I wasn't too far from my lot so I get it back into first and it grinds less and I idle back to my lot. I look it over but I dont have any tools there so I head back to the house.
Now that I think about it did some thing internal let the output shaft back out and break that housing? Did the housing freeze to the shaft and blow the part out?

Think the transmission is dead or is it just a replacement tail housing? either sucks because I have a 1/8th a mile on this truck now

 

[frank8003]

How did the truck get to where you first drove it from?

 

[DB556]

I had it towed to the lot, the HH needed a new button retainer.

 

[gimpyrobb]

Looks like its snapped, no way to tell for sure till you pull it.

I might have a parts trans with one on it.

 

[DB556]

Looks like its snapped, no way to tell for sure till you pull it.

I might have a parts trans with one on it.

I limped it back so I dont think the output shaft snapped unless is was moving the deuce through friction of the broken pieces.
I'll have to see if I can get down there with a tool set this week after work and pull the cover.
But I'll still have to find a replacement for that tail section.

 

[Evil Dr. Porkchop]

I have one with the exact same problem, not sure what caused it and I haven’t had a chance to look at it. I’ll be keeping an eye on this thread; hopefully the damage isn’t too bad.

 

[davidb56]

Id guess the snap ring on the other end (input shaft) might have broke first, allowing everything to shift back. you have to pull the transmission to fix that. If the output shaft bearing gave up, you still have to pull the transmission to replace it. I would be wary of just replacing the bearing retainer in place without figuring out Why it broke. That could live you stranded farther away some other time.

 

[gringeltaube]

The only thing that holds the whole mainshaft assembly in place is the rear bearing snapring and that bearing retainer. If the retainer breaks (like shown in the pics) the MS will shift backwards (due to the axial component of force from the helical gears). About 1/8" is enough for the 3rd gear sync. to come into contact with the 3rd main gear, causing the MS to spin in 3rd speed, even with the shifter in Neutral. Then, when trying to shift into any other gear it will cause that grinding sound.

This kind of failure is not something we see every day. As for the possible cause(s): 1) Maybe a sudden (accidental) release of the clutch, in either 2nd, 3rd, and 5th gear (in case of the 3053). Again, all helical gears create a significant axial component, constantly pushing the MS rearward. Any such abuse will multiply that force.

2) It has happened before that someone smarter than Spicer... decided to skip the original gasket and only use RTV on the retainer. That can be done, but only after some machining, making the recess a bit deeper, for the bearing and snapring. Otherwise, when tightening the bolts, the retainer will deform and most likely crack all around. Keep in mind that these are cast iron parts.

3) Not all bearing retainers are created equally strong. Some have more material in the critical area, others have less. For reference, a "good" retainer weighs 32 oz or more. Less than 26 oz. I would consider a "weak" part.


Of course you need to remove the top cover and inspect your transmission. It is very possible that you really only need to replace that retainer - which is an easy job, without having to pull out the whole transmission.

 

[DB556]

The only thing that holds the whole mainshaft assembly in place is the rear bearing snapring and that bearing retainer. If the retainer breaks (like shown in the pics) the MS will shift backwards (due to the axial component of force from the helical gears). About 1/8" is enough for the 3rd gear sync. to come into contact with the 3rd main gear, causing the MS to spin in 3rd speed, even with the shifter in Neutral. Then, when trying to shift into any other gear it will cause that grinding sound.

This kind of failure is not something we see every day. As for the possible cause(s): 1) Maybe a sudden (accidental) release of the clutch, in either 2nd, 3rd, and 5th gear (in case of the 3053). Again, all helical gears create a significant axial component, constantly pushing the MS rearward. Any such abuse will multiply that force.
2) It has happened before that someone smarter than Spicer... decided to skip the original gasket and only use RTV on the retainer. That can be done, but only after some machining, making the recess a bit deeper, for the bearing and snapring. Otherwise, when tightening the bolts, the retainer will deform and most likely crack all around. Keep in mind that these are cast iron parts.
3) Not all bearing retainers are created equally strong. Some have more material in the critical area, others have less. For reference, a "good" retainer weighs 32 oz or more. Less than 26 oz. I would consider a "weak" part.
Of course you need to remove the top cover and inspect your transmission. It is very possible that you really only need to replace that retainer - which is an easy job, without having to pull out the whole transmission.

That sound like exactly what happen other than I was shifting into 4th. I'll see if I can get down there after work tomorrow with a tool kit and pull the top cover. Hopefully it is just the bearing retainer.
I'm thinking does the rear output bearing sit flush with the case? its out about 3/16 of a inch.

Hopefully today is a productive day I need to lower the transmission mount on my Jeep TJ the NV4500 I swapped in is to high and causing to tight of a driveshaft angle.
Need to start driving the jeep again so I can work on the injector pump in my vw rabbit pickup. Its starting to pulse and high rev at stops so the governor is not springing back.
I really need to stop having project vehicles....So I got a deuce and a half...

 

[Floridianson]

Looks like its snapped, no way to tell for sure till you pull it.
I might have a parts trans with one on it.

Thanks and I think I have a parts trans too if all else fails. I was going to take some stuff to the scrap yard the other day and thought I saw one in all my mess.

 

[waayfast]

The only thing that holds the whole mainshaft assembly in place is the rear bearing snapring and that bearing retainer. If the retainer breaks (like shown in the pics) the MS will shift backwards (due to the axial component of force from the helical gears). About 1/8" is enough for the 3rd gear sync. to come into contact with the 3rd main gear, causing the MS to spin in 3rd speed, even with the shifter in Neutral. Then, when trying to shift into any other gear it will cause that grinding sound.

This kind of failure is not something we see every day. As for the possible cause(s): 1) Maybe a sudden (accidental) release of the clutch, in either 2nd, 3rd, and 5th gear (in case of the 3053). Again, all helical gears create a significant axial component, constantly pushing the MS rearward. Any such abuse will multiply that force.

2) It has happened before that someone smarter than Spicer... decided to skip the original gasket and only use RTV on the retainer. That can be done, but only after some machining, making the recess a bit deeper, for the bearing and snapring. Otherwise, when tightening the bolts, the retainer will deform and most likely crack all around. Keep in mind that these are cast iron parts.

3) Not all bearing retainers are created equally strong. Some have more material in the critical area, others have less. For reference, a "good" retainer weighs 32 oz or more. Less than 26 oz. I would consider a "weak" part.


Of course you need to remove the top cover and inspect your transmission. It is very possible that you really only need to replace that retainer - which is an easy job, without having to pull out the whole transmission.

Just gotta love this site!! Priceless, time saving information on here everyday!! Thanks folks!

Jim

 

[gringeltaube]

.......... I'm thinking does the rear output bearing sit flush with the case? its out about 3/16 of a inch.
...

No way can it be flush! It's a 308 NR- type of bearing, which means it takes a snapring (#NR90). That makes it protrude exactly 0.2197" (+/- 0.006), according to the bearing books.

The question is if it has been- or if it can move- further out than that, after the retainer broke?

 

[Floridianson]

Yep G is the man here and he needs to write the book.

 

[Scar59]

BD,
You just bought that truck, what kind of warranty did you get with it? Hope it wasn't "50 feet or the fence, what ever comes first"
Good luck brother, you're in good hands here.

 

[DB556]

BD,
You just bought that truck, what kind of warranty did you get with it? Hope it wasn't "50 feet or the fence, what ever comes first"
Good luck brother, you're in good hands here.

the warranty expired some time in the 1970's
And I dont think GSA auctions is going to issue the elusive 50year extended warranty

 

[cattlerepairman]

Classifieds...guy in Cincinatti selling takeout trannys....

 

[DB556]

Well I finally have a day to go down and look at it, now that its down pouring and I'll get soaked....

But I'm packing up sockets and tools anybody know the size socket for the transmission output flange nut? I'm looking at pictures I'm guessing 1 1/8" or 1 1/4"

 

[DB556]

Well needless to say this transmission is dead I might be able to splice 2 or 3 together to make a working unit.
I don't think there is a single gear except first and reverse that is not missing teeth. From looking at it I see the 4th/5th syncro is broken, and the pins are in the bottom of the pan.
I was making the shift from 3rd into 4th, so that explains why I was able to drive it around the block/storage yard. I never got it into 4th/5th before.
Time to find a 3053a transmission to swap in, and to think about what other medium truck transmissions have a SAE #3 housing that are cheap and durable.

But on the bright side I did get my electric wipers, and new air drains in......

 

[davidb56]

Sorry to see/hear the bad news. I bet you can find one in your area at a good price. I think they are actually cheaper for a rebuilt one, than the one in my F350 truck.

 

[davidb56]

theres one on *bay for 500$ right now.