Tranny yoke 70 muncie

[Kurt France]

I am having a problem putting in a new yoke in my muncie. The transmission has just been rebuilt and the yoke is new and measures 3.5" long and is 1.5" thick, it slides in an inch or so then stops and will not go further.

Any help is appreciated.

Thanks
Kurt

[lyndon sharpton]

Re: Tranny yoke 70 muncie

are you sure it is the right yoke?, a 70 yoke is course spline an in 71 went to fine spline.

[lyndon sharpton]

Re: Tranny yoke 70 muncie

what was I thinking that is the input shaft that was defferent!

[Joe L.]

Re: Tranny yoke 70 muncie

lyndon-----

Yes, the input shafts were different for 1970 versus 1971. However, the output shafts and yokes were also different for 1970 versus 1971. The 1970 output shaft was 26 spline; the 1971 output shaft was 32 spline. However, there is no way that a 1971 yoke could even be inserted, at all, into a 1970 extension housing,

[lyndon sharpton]

Re: Tranny yoke 70 muncie

if you get a big enough hammer!

[Dennis D.]

Re: Tranny yoke 70 muncie

Subject dear to my heart. I searched forever to find the correct trans yoke for my 70. Fortunately, with a bunch of help here and elsewhere I got what I needed.

Quick history. I have the correct muncie, buy I had a 71 driveshaft. I did have the yokes to accomplish the mismatch. When I wanted to install the correct driveshaft, thats when the problems began.

I'm sensing your issue isn't with the spline, but if you have a repro yoke it won't work. The distance from where the shaft ends to the driveshaft yoke mount is way to long. To further confuse the issue, the specs don't even give a measurement fot that distance. I may still have the pics of the original yoke compared to the repro. I'll try to dig them up. You can search the archives not more than 6-8 months ago. I posted for this info and Joe Lucia provided the lengths that helps a great deal.

I also spoke to a manufacturer in California who was aware of this problem, and was in the process of tooling for the correct piece. Seems a lot of us have a problem. He actually gave me a part number for when it was ready for sale. I'll look for that as well.

[Kurt France]

Re: Tranny yoke 70 muncie

Thanks for the response. I have read your stuff in the archives and have had similar problems...choke rod etc.

My problem wasnt in the length is was more of a width problem. It seems to get to the seal/bushing area then is stuck, I could hammer it but then the yoke will not turn because the fit is too tight or I may cause damage, I havent hammered much yet, I thought it should slip in.

I was worried my yoke was too wide, or my trans shaft was bent or if more force is required. I will check the box part # when I get home.

[Mark #28455]

output shaft bushing may be kinked

When the trans output bushing was inserted in the tailhousing, it may have been kinked or a burr may have been raised, I had a similar problem on a cam bearing in my block.
Mark

[Kurt France]

Re: output shaft bushing may be kinked

I pulled the tailshaft housing and got a new bushing to install. How tight should this bushing be...how much force is needed to get the yoke through the bushing. The bare bushing (not installed) will not slide easily on the yoke, it could go on with some force...like hammer force.

My new yoke is part #3868728 which (per the archives) is correct for a 70BB 4speed.

I have not started hammering yet.

[mike mccagh]

Re: output shaft bushing may be kinked

i'd press the bushing in the tail stock, then hone the bushing so that the yoke is a slip fit.if you'd prefer not having the local machine shop do the honing, a wheel cylinder hone will work but it'll take a while.give hammer to bubba. good luck, mike

[Dennis D.]

Re: output shaft bushing may be kinked

The new bushing I installed fit snug over the yoke before I installed it. Didn't need to force it. The bushing I installed has grooves and dimples, I assume for lubricating. It was exactly like the original one I replaced, so I'm fairly sure is was correct.

It also wasn't a solid sleeve shape.(pipe like). It was cut along the side to allow it to compress as needed to fit the aluminum tailshaft. Otherwise I suspect a slightly oversized, solid sleeve bushing could break the housing.

If this is what you have, I can't imagine it not fitting over your yoke prior to installing given the,"expanding joint", action of the bushing.

[Mike McKown]

Whatever shape or size

your driveshaft yoke should be an easy slip fit into the transmission tailhousing. If your extension housing is off the main case, try to slide it through the bushing. If it takes force, something is obviously wrong. At this point, you could either ream the bushing or take some metal off your yoke. Just don't hammer on it. If you already have the extension housing installed and you're trying to slide the yoke in through the bushing AND on the output shaft splines and it takes force, you may have a twisted output shaft.

[Joe L.]

Re: output shaft bushing may be kinked

Kurt-----

Assuming that you have the correct bushing (currently GM #6260048), it should not require force to install the yoke shaft through it. So, if you have the correct bushing, I suspect that it's been deformed in some way. Installing it may correct the deformity (or, may just complicate the installation process for the bushing and produce undesirable results/consequences).

[Mark #28455]

babbit type bushing

The babbit type bushing has a strong backing with a softer bearing surface. If you hone it to any extent it will remove the bearing surface and your NOS output shaft will be running on the bare backing surface and likely will not last very long.
Mark

[Craig S.]

Re: babbit type bushing

Plus babbit is soft and would imbed hone stone particles....creating an abrasive situation you definitely don't want Craig