Suburban 3 speed to an 8 speed trans?

[BHunter 1,700]

Hi everyone. 
Has anyone converted a Suburban to use an 8 speed trans? My 3 speed is trash and it’s easy to find newer transmissions. 

[ri702bill 8,482]

If it has a Unidrive already - it's a "bolt-in with modifications" Not a Unidrive now - perhaps someone else has done this and will share.....

Bill

[BHunter 1,700]

8 minutes ago, ri702bill said:

If it has a Unidrive already - it's a "bolt-in with modifications" Not a Unidrive now - perhaps someone else has done this and will share.....

Bill

It has the original 3 piece trans in it. 
I was thinking of attaching a square plate on the rear of the suburban frame and bolting on an 8 speed 

[ri702bill 8,482]

You may wish to see the posting by @stevasaurus, I believe - regarding the welded "adapter" to install a Unidrive into an early tractor. He did a 4 speed.... he is the transmission guy...

Bill

[953 nut 55,743]

@857 horse , Howard, did a build about ten years ago using a 401 Suburban and an eight speed. The adapter added several inches to the length and bolted to the Suburban without any modification. He did a first class job and also made up some adapters to run 4" hubcaps on the 12" wheel on the rear, very slick. I don't know if he ever did a build thread on it. This is al I could find, I think @stevasaurus may have good pictures of it.

 

[Pullstart 63,081]

@Lane Ranger has an adapter for this.  I know it’s not for sale, but he has pictures to reference at least!

[stevasaurus 22,856]

I don't know why you guys keep thinking I did things I did not do.  Let's see...guys that put 8 speed transmissions in a suburban.

  1. Wallfish

  2. Howard

  3. RacinBob ???

  4. Pullstart ???

  5. WHX??

  6. Achto

  7. Shynon

  8. Mike's RJ

  9. A host of others

10. and more to come...but not me  

[wallfish 17,078]

23 hours ago, BHunter said:

I was thinking of attaching a square plate on the rear of the suburban frame and bolting on an 8 speed 

If you cut the rear off of an 8 speed tractor frame,  those frame rails will fit right over the suburban frame and might be bolted on with the 6 original trans bolt holes. This will also give it the needed clutch rod arms and idler pulley to connect a pedal to. Then you will need to decide if that single pedal should also do the brake like 1 pedal tractors do or if adding a separate brake pedal for the brake like 2 pedal tractors is better for the build. Either way there's going to be some fabrication/tinkering.

If you build your own adapter you can still use those clutch/idler parts from the original 3 speed trans.

It will need either a bigger drive pulley on the engine or a smaller trans pulley to match the original speeds for the 8 speed trans. It would be slow with both of the original pulleys. Faster with some pulley size modifications. Easier to change the trans pulley to a 4" with 1/2" V IMO 

[953 nut 55,743]

22 hours ago, 953 nut said:

I think @stevasaurus may have good pictures of it.

 

1 hour ago, stevasaurus said:

don't know why you guys keep thinking I did things I did not do

I remember you posting some information about Howard's 401-8 speed and the trick rear hubcaps but don't remember when,       perhaps six or seven years ago. Come on Steve, a young guy like you should remember that!  

[stevasaurus 22,856]

I remember what and when I posted that @953 nut , but it was not about putting in an 8 speed transmission into a suburban.  It was about bending wire to serve as a belt guard (clutch) for Howard's RJ.  Howard took the pictures, Wallfish did the work, I watched and learned.  Howard sent me the pictures so I could instruct others with that issue.  

   I may have a picture of a suburban with an 8 speed in it, but any pictures I have would, not be for showing how it was done., and how the linkage looks.  

 

 

Edited December 11, 2022 by stevasaurus

[wallfish 17,078]

Ah, Howard's belt guardless pot metal pulley and no clutching action at his first big show! A quick field dressing in the road to get it shifting and going smoothly only to loose a tire in the back stretch. Howard made lots of friends his first year there! Kind of miss him posting on here and he used to be pretty active too.

It's become a pit stop at the show tent now. Always fixing or putting together something on our own tractors or someone else's.

[BHunter 1,700]

17 hours ago, wallfish said:

If you cut the rear off of an 8 speed tractor frame,  those frame rails will fit right over the suburban frame and might be bolted on with the 6 original trans bolt holes. This will also give it the needed clutch rod arms and idler pulley to connect a pedal to. Then you will need to decide if that single pedal should also do the brake like 1 pedal tractors do or if adding a separate brake pedal for the brake like 2 pedal tractors is better for the build. Either way there's going to be some fabrication/tinkering.

If you build your own adapter you can still use those clutch/idler parts from the original 3 speed trans.

It will need either a bigger drive pulley on the engine or a smaller trans pulley to match the original speeds for the 8 speed trans. It would be slow with both of the original pulleys. Faster with some pulley size modifications. Easier to change the trans pulley to a 4" with 1/2" V IMO 

Thanks @wallfish. I appreciate all the info. I planned to make a bolt on adapter but I like your idea about using the 8 speed frame rails. My son wants to keep the 3 speed  but the price of the rebuild kit with bearings is over 250.00.  I found a complete 312-8 tractor for 50.00. I enjoy fabricating so I don’t mind doing the swap. 

[stevasaurus 22,856]

Right John.  That was a great day at the show...  

[953 nut 55,743]

On 12/10/2022 at 6:23 PM, 953 nut said:

Come on Steve, a young guy like you should remember that! 

 

21 hours ago, stevasaurus said:

I remember what and when I posted that @953 nut

Thanks @stevasaurus, those were the pictures I remembered seeing.