3206 Diff Lock Question

carhopper · #1 09-30-2012, 08:54 AM

I have a 3206 and I love the diff lock, but when mowing the lawn and I hit the brakes, it locks the diff by default and is slow to release. This causes the tractor to push through the turns until it releases. I think this is normal because it even says in the manual:

"NOTE: Because of the load on the internal engagement mechanism, releasing the diff. lock pedal may not always disengage the differential lock.It may be necessary to slow the tractor, or reverse the direction of travel, to disengage the differential lock."

I am thinking of removing or adjusting out the linkage that makes this happen. Has anybody else done this? I cleaned some debris around the diff lock mechanism and it is much better, but still sticks until you release the load and take off slowly. My yard is big, but has lots of obstructions that requires tight turns and this is annoying.

I put on some V61 5-rib tires this weekend and it helps stick the turns tremendously from the turf savers, but the problem is still there.

Oak · #2 09-30-2012, 11:45 AM

Carhopper, why are you using the brakes? When I release the forward pedal the tractor will stop moving. The differential pedal is a cable and has nothing to do with the brake pedal. I'm thinking that there may be something else causing your problem.

cub123 · #3 09-30-2012, 11:49 AM

I'm finding it hard to understand why it locks the diff when you hit the brakes

Really with a hydo you shouldn't need the brakes when mowing at all, because the hydro brakes naturally when you let off. However it is normal for the diff to take time to release once locked.

carhopper · #4 09-30-2012, 01:49 PM

It's actually designed to lock the diff when you hit the brakes. Since the disc is on one wheel, on a unit without a diff lock only 1 wheel locks. With the 3206 both back wheels lock. Here is another caption from the manual:

"Depressing the brake pedal will also engage the transmission differential
lock. Always make certain the diff. lock disengages when the brake pedal is
released."

You're right, it does almost instantly stop when I let off of the forward pedal and that's fine on flat terrain. When I use cruise control, I have to press the brake to release because I already have the forward pedal all the way forward and tapping that doesn't release the cruise all the time. I'll practice not hitting the brake at all unless I'm pulling the trailer down hill, and even then I should be able to press the reverse slightly to act as a brake.

Oak · #5 09-30-2012, 03:29 PM

I believe you carhopper but I can't find that in my 3205 manual. What page is that on?

carhopper · #6 09-30-2012, 07:43 PM

Page 10 in my manual. Maybe the 3205 is different.

jsoluna · #7 10-02-2012, 05:30 PM

I own a 3205 as well, and I ended up having to swap out my difflock rearend for an open diff rear from a 3100 Series last winter (long story), so I've been through the entire linkage mechanism and rearend assemblies.

The reason difflock engages with the brake is because the way the linkage is designed. If you look up under the tractor you'll see the rod that is connected to your brake pedal goes from one side of the tractor to the other, and on the opposite side is the difflock pedal and cable - which runs back to the trans to engage the difflock collar.

It is very important that you don't try to brake when going at full speed with the difflock models. You're not just braking.....you're also moving the collar inside the differential that will lock both axles together. If you brake hard, you'll eventually shear the difflock pins and then you're in a world of hurt!!!! I priced just the parts to repair a grenaded 3205's rear and it wasn't even the least bit humorous

carhopper · #8 10-02-2012, 07:18 PM

I really need the diff lock, so I'm going to remove the linkage that locks the diff when I hit the brakes.

jsoluna · #9 10-02-2012, 07:28 PM

I don't think its possible...without removing the rod that the brake pedal pivots on. Lemme see if I can snag a pic real quick. I have the deck off for cleaning right now....

jsoluna · #10 10-02-2012, 08:02 PM

Here you can see the two rods that run from frame rail to frame rail. (Excuse the grease...this Cub gets run commercially so it doesn't have much down time until about this time of year) The one towards the front of the tractor (closest to steering unit) is for the brake pedal. Its a long steel rod, with a cam and springs in the middle to move the forward and reverse pedals to the neutral position. The rod runs through the frame on either side, supported by bronze bearings. On the far side it comes through the frame and then into a smaller rod for the difflock pedal:

Problem is that the rod is connected directly to the difflock pedal....i may have been too vague in my previous post. There technically is not any linkage between the brake pedal and the difflock pedal - they move in unison.