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Discussion Starter · #1 ·
Hi,

I know there have been threads in the past that talk about lowing the overall RPM's of the 825i Gator, and how to lower the exhaust noise level. I have recently done both and thought I would share my information. I have Kanati Mongrel 28" tires installed.

Exhaust noise:

I purchased a Silent Rider brand muffler for the 825i. As advertised, it immediately lowered the exhaust noise. From idle to wide open, you no longer get that "raspy" exhaust note. You can actually hear your tires and engine's mechanical noise at cruising speed (20 mph). I believe it gives a little more torque down low, but gives up a little top end punch.

Lowering the primary clutch engagement RPM:

I purchased the weights from a 2013 855D primary clutch (AM140452 $5), and the Team Industries 30-810005 primary spring ($25). This spring is red with a purple stripe (55/155 lbs). The diesel weights will need to be shortened 1/4" to fit into the 825i clutch basket. These weights are hardened to the 1/4" stock removal will need to be removed with a mill or cut off wheel.

Results:

Clutch starts engaging at 1400 rpm.

2000 rpm = 5 mph
2500 rpm = 9 mph
3000 rpm = 17 mph
3500 rpm = 25 mph
4000 rpm = 29 mph

I do not have a straight and flat enough area to test over 4000 rpm. Low end towing power is great. I hope this helps everyone.

825i primary clutch modifications.jpg
 
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Hi,

I know there have been threads in the past that talk about lowing the overall RPM's of the 825i Gator, and how to lower the exhaust noise level. I have recently done both and thought I would share my information. I have Kanati Mongrel 28" tires installed.

Exhaust noise:

I purchased a Silent Rider brand muffler for the 825i. As advertised, it immediately lowered the exhaust noise. From idle to wide open, you no longer get that "raspy" exhaust note. You can actually hear your tires and engine's mechanical noise at cruising speed (20 mph). I believe it gives a little more torque down low, but gives up a little top end punch.

Lowering the primary clutch engagement RPM:

I purchased the weights from a 2013 855D primary clutch (AM140452 $5), and the Team Industries 30-810005 primary spring ($25). This spring is red with a purple stripe (55/155 lbs). The diesel weights will need to be shortened 1/4" to fit into the 825i clutch basket. These weights are hardened to the 1/4" stock removal will need to be removed with a mill or cut off wheel.

Results:

Clutch starts engaging at 1400 rpm.

2000 rpm = 5 mph
2500 rpm = 9 mph
3000 rpm = 17 mph
3500 rpm = 25 mph
4000 rpm = 29 mph

I do not have a straight and flat enough area to test over 4000 rpm. Low end towing power is great. I hope this helps everyone.

View attachment 483
I have the Silent Rider but have not installed it yet. I would like to see that kind of improvement.
 

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Just installed new spring and weights. Before going up my driveway at 15 mph was 4,800 RPM now its 3,700. 10 mph was 4,300 and now 3,250. Didn't do many other speed checks as their were matching the above. This was a good upgrade and I only have 7.2 hours so far.:)

Installed front GLASS with wiper and rear panel with sliding window yesterday.

Ordering Silent Rider soon.

Thank you Arzdog.:D
 

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Discussion Starter · #4 · (Edited)
I'm glad it worked for you!

zr2blz, how do you like the rear glass panel? I have the Kolpin plexiglass rear windshield. I like it, but it is pretty thin and it flexes a lot.

I have found 1 flaw with the Silent Rider muffler. I just installed the hydraulic bed lift. When I went to the full up position, it dented the Silent Rider muffler guard. It still works ok, just has a crease the length of the guard. After the first time, it doesn't hit anymore!
 

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I'm glad it worked for you!

zr2blz, how do you like the rear glass panel? I have the Kolpin plexiglass rear windshield. I like it, but it is pretty thin and it flexes a lot.
We only put 1/2 mile on since install of windows. We just don't use the gator much. We use are '06 Honda ATV forman a lot more as I can get it out of garage without moving another car (it sits behind 26' camper). I have to move 2013 Sonic to get the gator out.
 

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videos

I would love to do this to my gator has anyone put anything online ( you tube showing how to do the mod. I'm fairly mechanically inclined but don't have a clue where to start?
 

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thanks everyone for the upgrade, i'm going to do this to mine. just installed new 14" rims with 215X70R14 winterforce tires. so much quieter. like the clutch idea.
 

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Just for the record here:

I have experimented with the trimmed diesel weights and the silver spring. Compared to my standard, early 825i clutch configuration, it engaged at a higher RPM, about 1450 as opposed to the 1200 or so of the standard clutch. It also snaps in and out as opposed to a smooth transition.

I have a jig that I use to trim the diesel weights if anyone wants to try them. I have a set of trimmed weights ready to go for that matter, if anyone wants to try it. Just because I found it objectionable, doesn't mean that you won't like it. After all a previous poster found it useful, so maybe you will to.

Just sayin'.
 

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thanks for clutch info. i was driving mine yesterday out to the lake to ice fish,it engages at about 12 -14, runs about 4700 at 30 mph. think i'll just leave the way it is. sure do like the smooth tires. thanks again.
 

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Which Silent Rider to use for 550 S4?

I see they offer a muffler for the 625i, 825i, 850i and the 860i.

I have a 550 S4 that I woudl liek to quiet down a little. Which one would work?
 

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Just for the record here:

I have experimented with the trimmed diesel weights and the silver spring. Compared to my standard, early 825i clutch configuration, it engaged at a higher RPM, about 1450 as opposed to the 1200 or so of the standard clutch. It also snaps in and out as opposed to a smooth transition.

I have a jig that I use to trim the diesel weights if anyone wants to try them. I have a set of trimmed weights ready to go for that matter, if anyone wants to try it. Just because I found it objectionable, doesn't mean that you won't like it. After all a previous poster found it useful, so maybe you will to.

Just sayin'.

I hate to dig up such an old thread, but why is your "early 825i" engaging at 1200 from the factory...while others are reporting upper 2000s before theirs will engage? Seems like most people are trying to make theirs do what yours does from the factory, versus this high-winding mess...
 

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There is no need to apologize for dragging up the thread. It has lots of good info albeit some of it outdated.

There were many problems with the early 825i clutches which led to a replacement clutch with the same part number. The replacements engage at about 1200 RPM IF the wear buttons are fit correctly and the belt spacing is correct.

In any clutch situation, you need to first test to see that the clutch is working smoothly, then go from there.
 

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After researching and reading for two days, I've came to learn that you are good at fixing the wear button clearance for people. Kudos to you, for that! What do you end up setting as a clearance for that? And do you know how tight(the clearance) they are from the factory?

Also, what is different about your replacement clutch from JD that has it engaging at 1200ish rpms? Maybe I could use the weights and spring from THAT primary, instead of the diesel ones...
 

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Also, I wonder why you got opposite results of other people, with the diesel weights and whatever spring you used? The weights are clearly heavier, which makes for a lower engagement rpm. The spring arzdog used has 55 lbs of initial force, but I think I've read that the stock gator spring is only around 43-44lbs. Did you use the TEAM spring that he used?
 

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After researching and reading for two days, I've came to learn that you are good at fixing the wear button clearance for people. Kudos to you, for that! What do you end up setting as a clearance for that? And do you know how tight(the clearance) they are from the factory?

Also, what is different about your replacement clutch from JD that has it engaging at 1200ish rpms? Maybe I could use the weights and spring from THAT primary, instead of the diesel ones...
The buttons are zero coearance. It is a matter of getting them loose without having a measurable clearance. A measurable clearance makes it noisy and even worse, does not allow for proper heat transfer. The buttons have to be hand fit by feel.

As far as the different results I got, remember, this is a very old thread. The earliest 825 clutches were different. The replacement clutch interchanges and carries the same part number, but it is different internally.
 

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Gotcha. Did you ever branch out into other vehicles? The 825 can't be the only one with ill-fitting wear buttons!

True. Would be nice to know what weights and spring is in your replacement. Do you have lower cruising RPMs, as well, or just a lower engagement RPM...with the typical 4000rpm/15mph combination?! haha
 

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I would do others if I determined a model with enough demand to warrant building a fixture. The JD's I do commonly need work because JD chooses not to pay for handfitting. This means that many of them require refurb. The same basic clutch is used by others but has much better quality which means there is not enough business opportunity to warrant fixture fabrication. Look at my stand in my avatar. It is made of heavy material and is lagged to my shopfloor. The forces required for disassembly and assembly are SIGNIFICANT so fixture fabrication is not a trivial task.

I am not at the shop right now so I dont know the exact spring, but it is yhe same in all 825 clutches. From experience I know that you can change springs and weights until blue in the face on a sticky clutch and it will make little difference. The key is having a properly fit clutch. If it is properly fit, the standard spring/weight combination will most likely serve you well.

Hope this helps.
 

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You're saying that all 825s have the same spring?

I don't have any problems engaging F N or R, so i imagine my clutch isn't sticking. My dad and I go on long rides, sometimes, and I'd just like to get the RPMs down. A lot! Going up some of those WV roads @ 15-20 mph is pushing 4500 rpms, and that's just insane.

I bought the diesel weights and spring and will be installing them tomorrow. I'll likely also test the two different springs at their spec'd heights and see how they compare. We also do a lot of tight, uphill, slow trail riding... so the diesel weights might make the RPMs too low... but there's always low range! And with the weights only being 6 bucks, if I don't like the rpms being that low, I'll get out the gram scales and do some grinding on the undersides to tailor my results.
 

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The clutch, and gear ratos are matched with the torque curve of the high revving Chery engine. Compared to other vehicles it may sound as if it is overspeeding, but the little engine is very happy at 4,500 RPM. The advantage of a continuously variable transmission system is that it keeps the engine generally at its most efficient speed. Changing the clutch profile moves it away from that sweet spot and defeats the overall engineering put into it.

In case you did not see it in the threads, you need to cut 1/4" from the end of the diesel weights. You need to do this accurately so that all weights weigh the same to prevent clutch imbalance. I used a precision scale to make them all the same weight, grinding mass ONLY off th end.
 
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