3 speed to 4 speed swap, help!?

[Montana54]

I just picked up a saginaw 4 speed because I chipped a tooth in the 3 speed. So my problem is I cant get the 3 speed out, if I could back it out another inch it would fall down but the crossmember is in the way. Is there a trick to getting these out or do I have to remove the crossmember?

[62gmc910]

Which cross member are you talking about ,in what truck???

[Montana54]

The one that goes under the tailshaft, it has the parking brake linkage mounted to it.

[62gmc910]

What truck ??????

[Montana54]

Im sorry I guess I need to put more thought into my posts, its a 65 c10 longbed, and the transmission did not mount to the crossmember the engine has two mounts up front and there are two more mounts on the bellhousing.

[62gmc910]

I can't picture the crossmember but can you losten the bolts and maybe gain enough room??

[Montana54]

Ok I just got it out. I had to slightly bend the slider brackets on the crossmember that guide the parking brake. Now I gotta get the 4 speed in and ill be ready to rock. thanks anyways.

[blackedoutharley]

Originally Posted by Montana54

Im sorry I guess I need to put more thought into my posts, its a 65 c10 longbed, and the transmission did not mount to the crossmember the engine has two mounts up front and there are two more mounts on the bellhousing.

Sounds like he is removing a SM420 granny box trans.

[Ham-er]

That particular crossmember has ONLY the E-Brake linkage on it right?
Drill out the rivets and use bolts when you put it back is what I did.

[LILRED66]

He is removing a 3-speed manual and installing an SM420. With the low hump tranny cover removed, you can remove four bolts attaching the tranny to the bell housing and remove the box, they you can remove the bell housing from the block. Reverse the order, to install. You will need a high hump tranny cover, if converting from a 3-speed column shift to a 4-speed floor shift.

[MikeN]

The last time I had to remove the transmission from my truck, I spent about 30 minutes drilling out the rivets attaching that crossmember you're discussing to the frame, and replaced with grade 8 bolts, lock washers, and nuts. It's the best 30 minutes and $3 I ever spent.

[LILRED66]

Good point MikeN, but I want to know where you got enough Grade 8 bolts, nuts and washers to attach the tranny cross member for only $3.00.

[protrash64]

Originally Posted by LILRED66

Good point MikeN, but I want to know where you got enough Grade 8 bolts, nuts and washers to attach the tranny cross member for only $3.00.

.....no doubt!! Price them yourself at Ace???

[Montana54]

Ok heres a quick update. First of all thanks for the responses, and I should have taken the crossmember out first thing but I wasted a day wiggling the tranny out. Then once it was out i did not want to go through that process with the 4 speed which by the way is a saginaw (monza), so then i drilled out the crossmember and the 4 speed was in within 15 minutes with the jack. Then because of how cheap I am instead of spending more money on a shifter I used the scrap metal I had and wiped up this little ghetto lightning rod set up (1st/2nd is far left, 3rd/4th is the middle lever and reverse is the little guy) so i put everything back together it bolted right in. But now I just took it for a quick spin and it sounds feels very lumpy, and it has a rough wine. Is this normal, just because it was sitting for a while, or is just worn out?

[MikeN]

Unfortunately, I think you're going to find that your 4-speed needs a total rebuild. Probably cheaper to find a decent used one, if you can get one from a trustworthy source.