4 Speed Transmission Damage from Fall

[HawkRod]

So I have some transmission woes from my 1970 Road Runner with 383 & 4 Speed.

I made my own K-Member cradle and when I had the engine and trans attached and was moving it around, the jack fell from the transmission and the tail shaft of the transmission fell and took a hit with all the weight of the entire assembly. If you care to read about that, see this thread:
http://www.forbbodiesonly.com/mopar...Rod-The-Restoration&p=910123361#post910123361

I am not experienced with 4 speed transmissions. This trans worked perfectly before, and I will most likely be replacing it soon. However, I need to use it for a while before it gets replaced. Just now, I put it in each gear, and it seemed to do that smoothly, but I realize that is probably a very limited test.

Questions:
1) Anyone have a replacement part (Pinion Bearing Retainer?) they can sell me?

2) Any suggestions for how to check for a bent shaft. See the third picture. I tried to put a dial indicator on it but there is a lot of slop in it with the busted retainer. Is this the right way to check it?

As always, I greatly appreciate the help and expertise from you all! :headbang:


When I pulled the trans off the bell housing, this is what I found:
View attachment 205183

A view from the other side:


Here is how I set up the dial indicator. However, I couldn't get a good reading. I think there is too much play in it with the retainer broken...

 

[69Bee]

There is usually a bit of play in the input shaft. You can get a new bearing retainer from:

Mancini: http://chucker54.stores.yahoo.net/bearret.html

Wayne Brewer Performance NEW: http://brewersperformance.com/products.asp?cat=228

Wayne Brewer Performance RECONDITIONED: http://brewersperformance.com/products.asp?cat=82

 

[nm9stheham]

Yeah, that point normally has some looseness in it with an unbroken reatiner so not a valid test (as you figured out). Unfortunately, if it were me, i would to dissassemble the trannie to get that input shaft out and check it along with other parts. It is retained on a bearing in the trannie housing that sits behind the bolt on plate portion of the bearing reatainer and throwout collar that is broken. IMO, you need to check:
- the input shaft outside of the trannie on some blocks
- look at the outer input shaft bearing
- look at where the above bearing it sets in a hole in the front of the housing to make sure that hole has not been bugered
- examine the mainshaft bearing inside the rear end of the input shaft
- examine the front of the mainshaft that rides on the bearing above
- check out the front gear on the countershaft that the input shaft meshes with and the countershaft bearings in the front

This input shaft took quite a lick to break the retainer like it did and may have gotten twisted upwards to an angle, and that could put totally abnormal stress all the part mentioned above. The good thing is that manual trannies are pretty straightforward to understand how to dis- and re-assemble.

 

[HawkRod]

Thanks to you both for some great information.

Unfortunately, it seems like the right thing to do is basically disassemble and check the transmission. With limited time, no previous experience doing this, and with the fact that I will be replacing the trans shortly, maybe I try just to check the outer input shaft bearing and casing?
If I do that (and they are OK), and you were a betting man, what do you think the likelihood of the rest being OK? I know this is not a 100% check, but if MOST LIKELY everything else is OK, then maybe I'll try that...

Again, I appreciate everyone's thoughts...

 

[coloradodave]

There is also the possibility that the bearing retainer snapped when someone tried to 'pull' the transmission into the bell housing with the bolts. The only reason I say this is because I read your prior post and see that you had to heli-coil the trans to bell housing bolt holes. I saw this once before when the bell housing bearing retainer locating hole was not concentric with the centerline of the crankshaft, and by pulling the trans toward the bell housing with the mounting bolts it put the retainer in a bind and snapped it exactly like yours.
When your trans fell, exactly what happened and what hit the floor first?

 

[sleepar]

Too bad you're feet wernt standing around under it when it fell Dave....you could have saved the day.
As long as the shaft isn't bent your ok ..the new retainer and bearing will fix any play it would have had if any...

 

[Hemi Rebel]

Well, the first thing you can do is take the 4 bolts out of the bearing retainer and remove whats left. Its odd that it broke like that considering the trans was still attached to the engine. I would have to disassembled the trans to inspect. The possibility of a chipped gear tooth or something exists.

 

[HawkRod]

There is also the possibility that the bearing retainer snapped when someone tried to 'pull' the transmission into the bell housing with the bolts. The only reason I say this is because I read your prior post and see that you had to heli-coil the trans to bell housing bolt holes. I saw this once before when the bell housing bearing retainer locating hole was not concentric with the centerline of the crankshaft, and by pulling the trans toward the bell housing with the mounting bolts it put the retainer in a bind and snapped it exactly like yours.
When your trans fell, exactly what happened and what hit the floor first?

Hi Dave,

I don't think it broke from 'pulling' it on with the bolts. What happened is that the trans was off the car and in good shape. It is an original transmission from an 80,000 mile 383 and was shifting very nicely when I took the car apart for the restoration. Once I had my engine and K-Member cleaned up, I put them on my homemade K-Member "cart". I then installed the transmission onto the engine. I installed it all the way to the bell housing by hand. I then inserted both top bolts and one bottom bolt (the driver's side was harder to get to, so I figured I would get to it later). They were only snug. I then supported the rear of the trans tailshaft with a jackstand on wheels. This formed the third support point of three: One under each end of the K-Member and one under the trans. When I moved the engine, a wheel on the trans jackstand hit a small stone and stopped suddenly. The trans tailshaft then tilted the jackstand sideways and fell off of it to the floor. The tailshaft hit the floor (the K-Member supports did not slip, so they held the K-member and engine up) and the force of it doing so ripped the one bolt out of the bottom of the bellhousing - that's the one I had to HeliCoil.

So mind you, I have done many dumb things, but in this case I did not force the tranny on the bellhousing. I am 99.9% sure it broke from the fall...

Here is a picture of the whole contraption right after it fell...


- - - Updated - - -

Too bad you're feet wernt standing around under it when it fell Dave....you could have saved the day.
As long as the shaft isn't bent your ok ..the new retainer and bearing will fix any play it would have had if any...

I don't think Dave would have thought that was good...

As far as the shaft - that is what I am trying to determine. Is it bent? If not, as you said, maybe I can get away with only a new retainer and bearing. The big question is how to figure out if it is bent without taking the whole thing apart...

- - - Updated - - -

Well, the first thing you can do is take the 4 bolts out of the bearing retainer and remove whats left. Its odd that it broke like that considering the trans was still attached to the engine. I would have to disassembled the trans to inspect. The possibility of a chipped gear tooth or something exists.

Yeah, I don't like the possibility of a chipped tooth. If that small piece makes it way into the wrong place it could be a really big problem...

Crap. What a PITA!!! :angryfire:

 

[sleepar]

You can't... take it apart... you have to anyway.. and inspect to see if the gears are ok... as mentioned...

Dave has been trolling my posts so I have been harassing him back... i dont think you cold break it that way.... anyways..
For the piece of mind... better now than on the side of the road

 

[Hemi Rebel]

On the bright side, you can take the opportunity to clean up and detail the trans. The engine, steering, suspension and k frame look so good. The trans deserves to look as good

 

[HawkRod]

On the bright side, you can take the opportunity to clean up and detail the trans. The engine, steering, suspension and k frame look so good. The trans deserves to look as good

LOL. I guess you are right. I was hoping to cheat a bit until got the replacement tranny in. I hate to do a major rebuild on a transmission I will only have in the car for a short time...

At any rate - I hear all of you, and of course you are right. I have to get the trans apart to check it out... Sigh - another item added to the to-do list...

Thanks again to everyone for all the help! :VB toast:

 

[Hemi Rebel]

What other trans are you going to run? In that case I guess you dont need to detail this one. Maybe just fast track the new one.

 

[Meep-Meep]

Just get a new bearing retainer and seal and bolt it on with a new gasket. The input shaft bearing is always loose and this is the nature of the Conrad style bearing. The pilot bushing supports the end of the input shaft and keeps things aligned.

 

[68 HEMI GTS]

those bearing retainers break at the drop of a hat. they'll beak if you pick the trans up wrong. doesn't look like your stand was very high, pop the side cover off and take a peak inside. if everything looks ok id bolt a new retainer on and call it good if it were me.

 

[2059]

2X with Meep and 68.

I snapped the retainer snout on my '69 Barracuda years ago when in the car. (340 Formula S) The pilot/crank bushing had worn out and there was enough play that over time it fractured then broke. The only thing that "snout" does is provide a sleeve for the throwout bearing. as said, when you put the new retainer on, take a look at the bearing, pop the side cover off check for missing teeth and such; strain the trans fluid through some cheese cloth and look for shavings.

Let us know what you find/do.

 

[HawkRod]

What other trans are you going to run? In that case I guess you dont need to detail this one. Maybe just fast track the new one.

That's part of the problem. I am on the waiting list for a Passon 855 (their 5 speed trans that has the same dimensions as the 833). There has been a lot of talk about how slow the production of these transmissions has been, and at the moment I am told that spring next year should be about when one should be ready for me.

Of course, there could be production delays. If it really is spring of next year, then my current (and original) trans will see no more duty than to move the car around and go for shakedown cruises. If delivery is late (very possible) I could end up needing to do something else. For my 50th birthday next year, I am driving the car across the country, so I really want some type of overdrive. The 855 is top of my list, followed by a gear vendors overdrive or a 4 speed 833 overdrive unit, beefed up and in 18 spline strength. Again, Passon has this and it is available now.

- - - Updated - - -

Just get a new bearing retainer and seal and bolt it on with a new gasket. The input shaft bearing is always loose and this is the nature of the Conrad style bearing. The pilot bushing supports the end of the input shaft and keeps things aligned.

I like the sound of this - not because I am trying to take stupid shortcuts but because I don't want to spend tons of time and money on a trans that I may not use long term. Now you have me thinking again...

- - - Updated - - -

those bearing retainers break at the drop of a hat. they'll beak if you pick the trans up wrong. doesn't look like your stand was very high, pop the side cover off and take a peak inside. if everything looks ok id bolt a new retainer on and call it good if it were me.

OK, now it sounds like some more folks think the chances might be good that things may be OK. The trans didn't take a huge shot, but there was some misalignment when the tail shaft was forced upwards after the one lonely bolt I had in there pulled out. It wasn't huge, the bottom of the trans was separated from the bell housing about 3/4" while the top was attached.

- - - Updated - - -

2X with Meep and 68.

I snapped the retainer snout on my '69 Barracuda years ago when in the car. (340 Formula S) The pilot/crank bushing had worn out and there was enough play that over time it fractured then broke. The only thing that "snout" does is provide a sleeve for the throwout bearing. as said, when you put the new retainer on, take a look at the bearing, pop the side cover off check for missing teeth and such; strain the trans fluid through some cheese cloth and look for shavings.

Let us know what you find/do.

OK. You guys have convinced me: I will inspect the front bearing and will also pull the cover off the side. If everything looks OK I will take a chance and put it in the car and see how it drives/shifts. I'll keep my fingers cross for no issues or weird drivetrain vibrations...

Again, many thanks to all!

 

[Meep-Meep]

Dropping the tranny on the ground is likely to cause more damage to the case than the gear teeth. The abuse those take behind a 20 YO and 400+ HP is far worse on the gears then a drop resulting a broken bearing retainer.

 

[HawkRod]

Dropping the tranny on the ground is likely to cause more damage to the case than the gear teeth. The abuse those take behind a 20 YO and 400+ HP is far worse on the gears then a drop resulting a broken bearing retainer.

Even if a visual determines that the teeth are in good shape, I am worried about a bent shaft causing a driveline vibration at speed. Driveline vibration can be a nightmare to find and deal with.

At least if I have one now, I will have a good suspect...

 

[Meep-Meep]

Agreed, but you would have to drop it "really good" to bend that shaft. That is either 8620 or 9310 material and has some hardness to it. Just the slop in the ball bearing would take some of the force out of the fall and distribute it, plus breaking the input retainer took some of the force as well. If anything got damaged it might be a brinell spot in the bearing, but the race and balls are harder yet. It all depends how it landed. Never a bad idea to check, especially since it's out, but I think it's unlikely anything happened other than the visual.

 

[HawkRod]

Hi everyone,

I figured I would update with what I decided to so. I also spoke with my father-in-law, who has built lots of transmissions in his 45 years of owning a speed shop. He also thought that the risk of damaging anything with the transmission was very slim. "Slap the new retainer on and forget it"!

Bottom line is he felt that the likelihood of additional transmission damage was very small. He was more worried about the clutch disk. The disk, he said, is fairly thin, and if the hub was bent, the disk could chatter and be a royal PITA.

For now, I replaced the transmission bearing retainer. Here are the old and reconditioned retainers


Retainer replaced. There was some caulk by the lower shaft hole, or whatever you call that. Maybe that took care of some weeping from that spot?