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skunkhome

Adjusting Shuttle Drive

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skunkhome
As I was operating my 3414 today, the reverse was strong as a bull but I noticed that the tractor was not pulling strong in forward. I knew the Shuttle was probably out of adjustment as there was no gap between the set collar and the Rod guide then the unit was in forward. I loosened the set collar lock screw and adjusted the gap according to specifications. Well.....! Then the tractor would not reverse at all and the forward (inside) pulley continued to turn in the neutral position. I thought Boy! I've done it now! (That wasn't exactly my choice of words.) What a mess I've made for myself! Once again I got out my AC 900 series manual and started from the beginning and re-adjusted the brake and then step by step through the Shuttle adjustments. On the third step of the shuttle neutral adjustment I discovered that there was apparently a field modification made to the neutral brake pad. The tractor did not have the expected round brake pad but instead had a block of bronze about 1/2" wide and 1-1/4" long bolted to the the brake lever with a 1/4" cap screw.


It of course was not at the proper clearance and was not readily adjustable. Luckily I was able to find a washer the right thickness to shim the block providing the required 1/8" clearance. After crossing that hurdle I was able to easily make all the rest of the adjustments. The result is a shuttle drive that works just like I suppose it was intended. There is wheel spinning power in both forward and reverse and the 4 speed shifts smoothly when lever is in the neutral position. I am concerned with the bronze block though it seems to work just fine. What is the OEM pad made of? It looks as if the threads in the brake lever may have been stripped out and thus will no longer accept the OEM brake pad. I guess if I can continue to shim it out it will work fine.

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Roy
The original, round brake pad looks like standard brake pad material. It is bonded to a threaded stud. The bronze pad should work fine but check it occasionally to make sure the bronze is wearing instead of the pulley. Glad you got it working OK. ^

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skunkhome
quote:
Originally posted by Roy
The original, round brake pad looks like standard brake pad material. It is bonded to a threaded stud. The bronze pad should work fine but check it occasionally to make sure the bronze is wearing instead of the pulley. Glad you got it working OK. ^
Roy, I examined the block today and indeed it looks like it is wearing instead of the sheave... are those brake pads still available? If so do you think there is enough clearance between the head and the brake lever to install a lock nut? I am sure the OEM pad won't work on my tractor without a stop/lock nut on both sides of the lever.

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gregc
Phil, from the looks of your picture of the bronze bar with your shim washer a new brake pad may fit with a lock nut. You may also need to grind the locknut down a little or find a thinner nut. The brake pad assembly #2174854SM is still available. It is 5/16" dia. You mentioned that the bronze bar was attached with a 1/4" capscrew. Maybe you've still got enough threads left in the brake lever to hold the new brake pad assembly.

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skunkhome
quote:
Originally posted by gregc
The brake pad assembly #2174854SM is still available. It is 5/16" dia. You mentioned that the bronze bar was attached with a 1/4" capscrew. Maybe you've still got enough threads left in the brake lever to hold the new brake pad assembly.
Greg, 5/16"? That is great news... I thought it was a smooth 1/4". It is so difficult to get a clear view of the end of the lever that I truly can't tell you what the condition of the "hole" is.

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haykarenhardy
I have some good used parts and a good brake pad/stud that are under the work bench, if you want to go that route give me a PM. ( if it works don't fix it ) }:) Stan

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rsnik
I have 2 shuttles and bought a couple of the brake pad/studs last winter. I fear they may now be making them in China or something. I got on one shuttle that I had adjusted perfectly and the transmission was grinding. I took a look and the pad had dropped off the stud leaving the sheave spinning. Been using the other shuttle. However, I checked the other shuttle recently and that pad has dropped off as well. I adjusted it to take out the slack of the missing pad but I can't run it that way for long. I am actually thinking of cutting a patch of leather out of an old boot and crazy gluing it on (I know, been watching too much Red And Green Show). Even if they don't last long I am getting a whole collection of studs with no pads to glue leather on.

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skunkhome
quote:
Originally posted by rsnik
I am actually thinking of cutting a patch of leather out of an old boot and crazy gluing it on (I know, been watching too much Red And Green Show). Even if they don't last long I am getting a whole collection of studs with no pads to glue leather on.
The leather may work if you use contact cement... don't know how it will hold up to abrasion.

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