Install transmission minus one dowel pin?

[MattL]

I bought a cracked and repaired 245 5-speed to swap into my car. The damage was to the bell housing, and the crack was welded to fix. Today I test fit the thing in order to determine mount placement, etc. Unfortunately, I couldn’t get both dowel pins to seat. I measured the distance between them and found that it’s roughly 1/16” greater than the same dimension on my 4-speed. The 3 o’clock pin/hole (looking towards the gearbox) seems to be the culprit. The weld was right next to it, so that makes sense. 
 

I believe I can get the transmission to mate if I take that pin out and just install a bolt. Am I crazy to consider that as a solution?

[Son of Marty]

Matt that seams a bit scary to me, the object of having the 2 tight fitting dowels beyond lining the tranny up  is to prevent tortional shifting of the  tranny, so that the input shaft is inline with the crank,any side loading here will lead quickly to damage to the engine tranny or clutch. But again I've never had to deal with your problem. Maybe you could get a machinist to make a off set bushing.

[tech71]

There’s been other posts about this  trans I think including some pics of the weld? If it’s the one I think it is then I have to say that  it was not welded/repaired very well at all and the crack is huge, more like a break than a crack.

 The fact that the alignment pin location has shifted attests to that.

If you manage to get it installed it may fail pretty fast and  if it comes apart again at high speed. It could fragment, seize, damage other components and possibly cause you to lose control of your car.  
If it’s the trans I’m thinking of ( I believe it is ) I would never install it on a car, too far gone. Sorry.
 

Spent a few years inspecting helicopter gear boxes  undergoing overhaul, had to go to school to be allowed to inspect weld repairs this is a FAIL, F-

Edited May 15, 2021 by tech71
Pics

[MattL]

12 hours ago, tech71 said:

There’s been other posts about this  trans I think including some pics of the weld? If it’s the one I think it is then I have to say that  it was not welded/repaired very well at all and the crack is huge, more like a break than a crack.

 The fact that the alignment pin location has shifted attests to that.

If you manage to get it installed it may fail pretty fast and  if it comes apart again at high speed. It could fragment, seize, damage other components and possibly cause you to lose control of your car.  
If it’s the trans I’m thinking of ( I believe it is ) I would never install it on a car, too far gone. Sorry.
 

Spent a few years inspecting helicopter gear boxes  undergoing overhaul, had to go to school to be allowed to inspect weld repairs

Yep, that’s the one. Thanks for the advice. Luckily, I have a “spare” unit that another generous FAQ member gave me for parts. I’m going to take them both to a pro in the hope he can create one good box out of the two of them. In the meantime, I’ll put the 4-speed back in. It’ll be good to drive the car again, at least!

Edited September 7, 2020 by MattL

[tech71]

I'm sorry you got hosed on this transmission but that case is just super questionable. I mean, where did it get "dropped" from? A cliff?

Glad you have a spare with hopefully an intact case.

 

By the way, if you end up with any extra, serviceable countershaft support bearings be sure to hang on to them, they are pure unobtanium.  Item # 13 in pic

Edited September 7, 2020 by tech71

[MattL]

I learn best through painful, expensive experience, so I feel like I've gotten my money's worth.  In all seriousness, though, it was deeply discounted due to the damage, so I don't feel like I got hosed. And I'm glad I ham-handed my way around this box instead of a really nice one. Assuming the Franken-Trans project is a success, I will have already gotten my stupid mistakes out of the way. And I'll be sure to keep an eye out for the bearings. 

 

Thanks again.

Edited September 7, 2020 by MattL

[tech71]

19 minutes ago, MattL said:

 In all seriousness, though, it was deeply discounted due to the damage

 

As it should have been, not discounted enough in my opinion  and It was listed and sold as "fully functioning" when clearly... it was not.   I'm done now?

Edited September 7, 2020 by tech71

[stone02]

Hey,

  i am not sure if this is possible but a good trans shop might

be able to use a front four speed case to replace the broken five

speed case. if this is possible then the older style of clutch slave

could be retained and less messaging of the tunnel might be also

a good thing. you could call and ask Metric Mechanic, they usually

give very solid advice.

stone

[MattL]

Hey Chris,

Today I actually talked with Gordon, the guy you put me in touch with. I’m going to take him the cracked box and the grimy spare, and see if he can merge them into something good. Thank you for the tip. 
Matt

[MattL]

For anybody following along at home: @tech71 called it! The “repaired” 5-speed unit I have is unusable and probably unsalvageable (lunched 4th/countershaft input gear, among other things), and the donor box @mvliotta kindly provided is unfortunately too far gone to be of use. (Thanks anyway, Vince - very kind of you to let me have that.) So, if anybody has a hot lead on a serviceable 245 — or even a 240 — I am all ears.