B-80 - 4 spd vs 8 spd transmissions

[OutdoorEnvy 1,510]

Hey folks I would like some experience feedback on the comparison between the 4 speed and 8 speed versions of the B-80.  Is the 4 spd strong like the 8 speed?  I assume implements are interchangeable without issue.  I didn't know some were 4 speeds so was curious of pros and cons and if 4 speeds are worth getting.  Thanks in advance!   

[ebinmaine 66,129]

As far as the B80 is concerned, 1974 and 5 were 4-speeds. 1976 and 7 were 8-speeds.

 

1974 and 5 were also a slightly shorter frame known as the Mid frame. Maybe 2 inches shorter than a Long frame if I remember right?

 

There is a difference in strength between a 4-speed and an 8-speed. Four speeds have four pinions inside the differential Bull gear.. Most 8-speeds, but not all, have eight pinions.

 

Is a four-speed, "less strong"? Well by definition, yes. But that, IMHO,  is a moot point because transmissions on these tractors are so overbuilt anyway..

 

My first Wheelhorse was a four-speed B80.

It was completely capable of doing any of the heavy towing that my 12 or 16 horse 8-speeds have ever done.

 

The only reason I sought out and eight speed was so I could get the low gear which is 1/4 the speed and that's very important to me for backing into tight places.

 

 

Is a 4-speed worth getting? Absolutely!

[ri702bill 8,004]

IMHO - go with the 8 speed. All implements interchange - and if you are going to use a tiller, the 4:1 reduction of low range allows you to "crawl" with the engine up at WOT - a similar 4 speed first gear is not low enough - reqiures constant clutching...

[ri702bill 8,004]

3 minutes ago, ebinmaine said:

Is a 4-speed worth getting? Absolutely!

AND - it could be upgraded to an 8 speed later.

When I got my 854 it had a not-worth-fixing 4 speed. Installed an 8 speed from a C81 donor - never looked back.

[ri702bill 8,004]

33 minutes ago, ri702bill said:

and if you are going to use a tiller, the 4:1 reduction of low range allows you to "crawl" with the engine up at WOT

Ditto for a snowblower - I usually run my 32" one on the 854 in Low second gear at WOT.

[OutdoorEnvy 1,510]

This will be mainly mowing with some snow plow and sleeve hitch work.  My friend is considering it as it popped up near by for a good price.  It's 4 spd and has a 38" mowing deck.  Just debating if he should wait out an 8 spd or not.

[Lee1977 6,516]

Low range isn't iused often, but it's nice to have when it's needed. Low range and low gear will usually get you out of a slick spot that the tractor will only spin in high range.

 

[Pullstart 61,979]

I don’t imagine a huge market where you are.  If it makes sense, get it now and keep an eye out for an 8 speed… whether in tractor form or transmission/swap.

[ebinmaine 66,129]

50 minutes ago, OutdoorEnvy said:

This will be mainly mowing with some snow plow and sleeve hitch work.  My friend is considering it as it popped up near by for a good price.  It's 4 spd and has a 38" mowing deck.  Just debating if he should wait out an 8 spd or not.

 

1 minute ago, Pullstart said:

I don’t imagine a huge market where you are.  If it makes sense, get it now and keep an eye out for an 8 speed… whether in tractor form or transmission/swap.

 

 

 

 

Not a bad idea there

[horseman with no horse 26]

i think the sr 64 reduction kit is worth mentioning too if the speed is gonna be considered, the crawl my 3 speed does with that thing, as well as the extra idlers for grip on the rear pulley is nice at WOT. also whats the difference between the 3 and 4 speeds? i know the standard 2 piece 3 speed transmissions were bevel gear diffs and the "heavy duty" was a 4 pinion, but other than that what would even be the physical difference between a 3 or 4 speed?

[Pullstart 61,979]

1 hour ago, horseman with no horse said:

i think the sr 64 reduction kit is worth mentioning too if the speed is gonna be considered, the crawl my 3 speed does with that thing, as well as the extra idlers for grip on the rear pulley is nice at WOT. also whats the difference between the 3 and 4 speeds? i know the standard 2 piece 3 speed transmissions were bevel gear diffs and the "heavy duty" was a 4 pinion, but other than that what would even be the physical difference between a 3 or 4 speed?

difference?  Not much.  The 3 and 6 speeds had one brake band.. and they changed what shaft the brake drum rides on and made those 4 and 8 speeds.  Same gear ratios, same rock solid design.

[Retired Wrencher 5,233]

I have an eight speed B80 darn good tractor. I have had many for speeds. They are all good. My wife likes a clean driveway in the winter so I blow first then use the tractor finish up. She says if it is not black it is not clean! This way I don’t  even put chains on. The eight speed is great for getting up ice also. Enjoy your day.

[chalky 4]

B80 1977 got a leak on the seal in behind the brake drum , can this seal be replace from the outside ? Or does the case have to be split opened . Thanks !

[ebinmaine 66,129]

41 minutes ago, chalky said:

B80 1977 got a leak on the seal in behind the brake drum , can this seal be replace from the outside ? Or does the case have to be split opened . Thanks !

 

 

 

 

 

All 4 Unidrive Manual transmission seals can be replaced from the outside. 

 

[squonk 40,622]

5 hours ago, chalky said:

B80 1977 got a leak on the seal in behind the brake drum , can this seal be replace from the outside ? Or does the case have to be split opened . Thanks !

Carefully drill a 1/16" hole on the seal ring. Insert tiny sheet metal screw. Pull it out with vise grips.

 

 

8 spd transmissions have 1 weak spot. The hi lo shifter fork bends and breaks easily and is NLA 

[chalky 4]

Thanks