My Tractor Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
Hello All,
Been checking out the My Tractor Forum and finally took the time to setup an account.
I have a question about a model L Gravely. My question is when you shift the hi/lo lever on the handle bar does this affect both the ground speed and the pto speed? Any help will be appreciated.
Thanks,
Doug
*
 

·
Premium Member
Joined
·
4,135 Posts
Welcome.

Short answer yes. The hi/lo controls the clutch pack which is driven right off the engine, and drives the rest of the transmission, including the PTO.

Not to be confused with the "third" control lever on an L8, which is under the right handlebar. That one controls the two-speed axle.
 

·
Daryl G
Joined
·
857 Posts
Douglas Lee,
Take a look at this screen shoot from one of the old Gravely manuals:

ground speeds gravely.png

The 'slow speed tractor' is the LS model, the 'medium speed tractor' is the LI model, and the 'regular speed tractor' is just the 'L' model.

Oddly, but once again, the GravelyManuals.com - OldGravelys.info: : site is not working... luckily I saved many of these on my computer.
 

·
Registered
Joined
·
128 Posts
And to just add a further twist, when you add gear reduction wheels (GRW) to any of the listed tractors they cut the ground speed in half (more or less). So an LS would be about 1 mph in high gear with the highest PTO speed at full engine speed. This is why the GRWs are recommended for the slow travel by high PTO speed jobs (like the rotary plow &/or snow blowers).
Can't use the GRW on the 8 speed tractors that I know of.

I do find the straight L tractor to be way too fast (travel speed) for most uses. But they do make a good trailer hauler.

I do have a 6 lead 2 speed axle set out of a 400 series 4 wheel tractor which I plan on adding to one of my 8 speed tractors. Should be interesting.

Just my opinion.
 

·
Premium Member
Joined
·
3,028 Posts
nhgravely,

Covertering a L8 to LI8 is a project, I have done one or two. Converting a LI to a two speed axle is a little easier. The job with an L8 is changing the lead worm. The 400 series Swiftamatic requires a six lead worm.

You say that you have a two speed axle from a 400 series four wheeler, is that a early 400 series or post summer of 1971 series Swiftamatic, new style or old style?

Are your L8's new style or old style? Three cog shifting componets or five cog shifting components? Do the cog shifting componets match your 400 series donner?

You will need the shifting clutch of a L8, to work with the donner 400 differential, the four hundred series shifting clutch will not work in a two wheeler.

I personally do not like the early Swiftamatics, they self de-struck sooner or later. That is why Gravely came out with the new style.

Yes, there are many old style Swiftamatics in good condition and they can last a long time with good maintenance.

Roger
 

·
Registered
Joined
·
599 Posts
I do find the straight L tractor to be way too fast (travel speed) for most uses. But they do make a good trailer hauler.
I agree with the above, except I have found a few instances where the high speed worked well. One requirement for me is a sulky when using a L in high, it's too hard to keep running after the tractor. But a sulky on a regular L, with the push blade and the trans in high, pushes a reasonable snowfall very well. The higher speed throws the snow a decent amount to the side and gets larger jobs done faster.

And if you have a very large yard, and only have the 30 inch mower, the L in high with a sulky will get the job done faster than you would have thought it could.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #8
Thank you all for the feedback, I see the numbers provided by Fireant911, the difference in hi/lo range is very clear now!
Doug
*
 

·
Registered
Joined
·
128 Posts
Franklin2:
I don't have a sulky so with the Model L I had to run all the time until I installed the GRWs.
Now it works great, just like an LS (which I also have).

Beaner2u:
Both of the C8s are of the serial number range for 1969 so I assume they are the old style Swiftys, with the 3 jaw clutch engagement shifter. The 400 setup I got (which is in like new condition) is a three jaw old style also so everything should work. I realize I have to tear down almost the entire tractor to do this, but the one I think I will be doing already needs a jug upgrade, a F/R clutch upgrade and maybe other things anyway. I do have an LI on the engine stand right now, but prefer to leave it as a 4 speed and maybe get another set of GRWs and have a really low geared tractor. Thanks for the input.
 
1 - 9 of 9 Posts
Top