P500 A faster P5, it is possible.....gearing increase

[Duckhunt]

In hindsight I think I may not have needed to grind clearance on the counter shaft gear, their is a 10mm spacer used on this model that would set the gear clear of the case. I might tear it back down this winter to inspect and install it then. So far I've put on about 500 miles since the change and am very happy with it.

I got the gear spacer yesterday. Only 4mm thick which is good. Hopefully it will work. Wheeler is all washed and on blocks, time to roll up sleeves tonight (and every other night this week...) Locker should be here end of day too.
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[Admin]

 

[Duckhunt]

I finally tore down the rear of the engine to put in the 906 gears. First of all excellent instructions! The hardest part was pulling the case off the shaft which I'll get to later and it wasn't that difficult I was just very, very careful.

That 4mm spacer WILL NOT WORK. And even if there was the clearance needed, with the spacer the drive gear over hangs the driven gear to the rear way too much, so that tells me on the Foremans they must mill more in the crank case and press the bearing in further, or somehow move the driven gear back too. Oh well. I really wanted to clearance the case since you only have to do about 240 + or - degrees around the gear, however as 906UP also realized the clearance is minimal so I just touched the gear with the grinder to avoid any shavings in the case. Besides, I forgot to throw a mic on the gears but on both new and old gears the drive gear is thicker and as 906UP's pictures show the drive gear is also recessed in the case more so no concern whatsoever. A good portion of the removed material would have never seen the driven gear anyway.

So everything came off very, very easy. As I've posted here, there, and everywhere I'm also doing locker and suspension mod so I pulled the front diff and shaft out first, going off 906UP's recommendation. However what I noticed is the case separated easily but the final shaft seal wanted to catch in one of the grooves on the "outside" of the final shaft as I pulled it off and the shaft wanted to come back with the case. Maybe this is where yours pulled through 906UP? Anyway I was very very cautious and careful and after trying a few things including having my What's-Her-Face put a little pressure on the end of the final shaft while I tried to pull the case I found in the end to pull the case and shaft out maybe 1/8" then while wedging some fingers between the cases I'd lightly tap the shaft back in (fwd) with a little brass hammer. Then pull both out 1/8", tap her in (just tap it in, give it a little tappy). Did that 3-4 times and presto! No front seal damage! Hopefully that makes sense...

 

[906UP]

Excellent job @Duckhunt , I guess I don't have to tear mine down again. Let me know what you think of the new gears, I'm quite happy with the set up.

 

[harleyjohn45]

I just found out the hard way, you cannot drive a street legal and licensed side by side on any paved road in Lincoln County New Mexico. It's my fault for not checking out the state law. While it's legal to ride an off road vehicle on a paved road in New Mexico, the counties have to opt in and only eleven have done so. Lincoln County has not opted in, so I got a 257.00 ticket. I will sell the unit, because I don't want to trailer 3 or 4 miles to the trail heads I want to ride on. Good knowing everyone here, this is a nice site.

 

[trigger]

I just found out the hard way, you cannot drive a street legal and licensed side by side on any paved road in Lincoln County New Mexico. It's my fault for not checking out the state law. While it's legal to ride an off road vehicle on a paved road in New Mexico, the counties have to opt in and only eleven have done so. Lincoln County has not opted in, so I got a 257.00 ticket. I will sell the unit, because I don't want to trailer 3 or 4 miles to the trail heads I want to ride on. Good knowing everyone here, this is a nice site.

Not even to the extreme right? Just because you can't ride on the road doesn't always mean you can't ride the shoulder or ditch line. Were you doing over 25 mph?

 

[LarryAmboy]

I just found out the hard way, you cannot drive a street legal and licensed side by side on any paved road in Lincoln County New Mexico. It's my fault for not checking out the state law. While it's legal to ride an off road vehicle on a paved road in New Mexico, the counties have to opt in and only eleven have done so. Lincoln County has not opted in, so I got a 257.00 ticket. I will sell the unit, because I don't want to trailer 3 or 4 miles to the trail heads I want to ride on. Good knowing everyone here, this is a nice site.

I think I would challenge that ticket. My understanding is there is a federal law that requires reciprocity for vehicles that are legally registered and plated in one state to be legal in another state.

Just because a cop writes a ticket doesn’t make it so. Often they don’t understand some of the laws.

 

[Duckhunt]

Excellent job @Duckhunt , I guess I don't have to tear mine down again. Let me know what you think of the new gears, I'm quite happy with the set up.

Yup very happy with the gears! Does exactly what you said, and exactly what I wanted! Low is now a little closer to a true 1st gear, can still start out in 2nd, 3rd & 4th are great trail gears, but the kicker is even though I only had enough "drag strip" on a section of forest road to hit 45mph, but I could still talk to my wife! Honest there wasn't a whole lot left maybe 47-48 with both us in it but that's fine. I like the 35-40 "cruise" speeds now at a lower rpm.

So my SpeedoDRD is either broke or I need to factory reset it and test impedance and frequency. I just did the quick number-value-enter (#5 blinks) I tried -30%, -33% (first), & -36% and all the speedo did on the dash was dance around, never past 20mph. No matter the gear it would rise erratically then fall eratically, 3,5,9,12,11,13,12,10,9... as you'd accelerate. But at least it didn't derate the engine I guess.

 

[906UP]

Yup very happy with the gears! Does exactly what you said, and exactly what I wanted! Low is now a little closer to a true 1st gear, can still start out in 2nd, 3rd & 4th are great trail gears, but the kicker is even though I only had enough "drag strip" on a section of forest road to hit 45mph, but I could still talk to my wife! Honest there wasn't a whole lot left maybe 47-48 with both us in it but that's fine. I like the 35-40 "cruise" speeds now at a lower rpm.

So my SpeedoDRD is either broke or I need to factory reset it and test impedance and frequency. I just did the quick number-value-enter (#5 blinks) I tried -30%, -33% (first), & -36% and all the speedo did on the dash was dance around, never past 20mph. No matter the gear it would rise erratically then fall eratically, 3,5,9,12,11,13,12,10,9... as you'd accelerate. But at least it didn't derate the engine I guess.

Awesome, glad you're happy with it. My speedo did the same at the beginning, I fiddled with the settings until it was happy. Did you shim the speed sensor a little bit? You'll want to make sure it isn't rubbing on the drive gear.

 

[Duckhunt]

I had to stack three 1/4" flat washers under it before it would clear. So I know that's good. I'll keep playing with it. Did you mess with any other setting or just the number value (percentage)?

 

[906UP]

I had to stack three 1/4" flat washers under it before it would clear. So I know that's good. I'll keep playing with it. Did you mess with any other setting or just the number value (percentage)?

I did by accident, fat fingered the setting.....somehow I got it back to the factory setting. Maybe send DRD an email about the other settings.

 

[Duckhunt]

I just wanted to put in a follow-up note in here in case people are considering this or following. The gears work awesome, Low is unnoticeable change (to me) and now in 5th upper 30's mph to low 40's mph is a pleasant cruise. But I had speedo calibration/ speed sensor reading issues causing an irratic speedometer, with and without the SpeedoDRD, and electronic-delayed shifting. On upshifts it would wait a good half second after the shift before firing the injector again. First, I thank @906UP for very much appreciated help. The new drive gear is APPROXIMATELY 5mm or .2" larger OD, or 2.5mm/.1" radius. This is an approximation by measuring the factory "old" gear and using pictures and CAD for calculating a size difference ratio of the two gears, neither of us ripped apart the case and measured the new larger gear. Now, @906UP is using a .1085" or 2.76mm spacer under the speed sensor, and I was using three .047" washers for .141" or 3.58mm total. I was .0325" or .82mm further spaced from the new driven gear. After installing a same sized spacer as @906UP I have corrected the speedo and shift-delay issues. The speed sensor spacing is that critical.

If you do this mod be sure the speed sensor has clearance, but also do not space too far. Unfortunately we do not know the exact tolerance of a spacer but .094" or 2.39mm (two of my washers) is interference, .1085"or 2.76mm works, and .141" or 3.58mm is too much. Again this is for the speed sensor spacing. Thanks again to @906UP for all the help.

 

[Spellmajr]

Think I am going to give this a try this summer. Doesn’t look to hard just time consuming. Mostly just removing and installing basic hardware. Only tricky part would be messing with the speedo.

 

[Duckhunt]

Nice! You'll like it. Probably wouldn't notice if you do a lot of mudding, crawling, hill climbing or sand dunes, but if you ever go on forest roads or "easy" atv trails the broader gears are definitely sweet!

@906UP got the final shaft seal issue resolved for us and I took care of the speed sensor spacing issue! Don't be afraid of the speedo LOL! Just keep the spacer for the sensor close to .100" (check clearance of gear) and programming the SpeedoDRD is cake walk. Watch the 1 minute video on their website and your good. On paper going from 25 teeth to 16 teeth is negative 36%, but I've played with mine and it can vary some and not make a difference performance wise.

 

[Montecresto]

I just found out the hard way, you cannot drive a street legal and licensed side by side on any paved road in Lincoln County New Mexico. It's my fault for not checking out the state law. While it's legal to ride an off road vehicle on a paved road in New Mexico, the counties have to opt in and only eleven have done so. Lincoln County has not opted in, so I got a 257.00 ticket. I will sell the unit, because I don't want to trailer 3 or 4 miles to the trail heads I want to ride on. Good knowing everyone here, this is a nice site.

You may not be in a position to do so, but what I did to overcome that issue was to buy property right on the edge of the Santa Fe National Forest so I can ride out my gate and half a mile down the county dirt road to a forest access road. I hate that you’re selling your ride and giving up for this.

 

[Spellmajr]

Nice! You'll like it. Probably wouldn't notice if you do a lot of mudding, crawling, hill climbing or sand dunes, but if you ever go on forest roads or "easy" atv trails the broader gears are definitely sweet!

@906UP got the final shaft seal issue resolved for us and I took care of the speed sensor spacing issue! Don't be afraid of the speedo LOL! Just keep the spacer for the sensor close to .100" (check clearance of gear) and programming the SpeedoDRD is cake walk. Watch the 1 minute video on their website and your good. On paper going from 25 teeth to 16 teeth is negative 36%, but I've played with mine and it can vary some and not make a difference performance wise.

I don’t mud or rock crawl. I use it a lot on places I can open it up. We have family land and a cabin by a ton of GOV woods. I load my dogs up and take my p500 back and forth a lot. Or I’ll go for a cruise down to the lake and back in it.

 

[906UP]

This

I don’t mud or rock crawl. I use it a lot on places I can open it up. We have family land and a cabin by a ton of GOV woods. I load my dogs up and take my p500 back and forth a lot. Or I’ll go for a cruise down to the lake and back in it.

This mod is really simple with basic hand tools if you have even the slightest bit of mechanical ability. Just take your time & follow my pics/instructions in post #1. The speedo spacing issue that @Duckhunt had was a fluke......or I just got lucky on the 1st try but now that we know sensor spacing it should be easy. I think between Duckhunt's speedo & my final seal issues we've got the bugs worked out. It really makes the P5 more fun without losing the utilitarian gearing. If you have any questions feel free to contact me.

 

[906UP]

Just want to add, don't get hung up on the speedo drd settings. The speedo isn't going to be accurate anymore regardless, the trick is to get the setting close enough so the ECU is happy and you dont get the "-" on the dash.

 

[Spellmajr]

This

This mod is really simple with basic hand tools if you have even the slightest bit of mechanical ability. Just take your time & follow my pics/instructions in post #1. The speedo spacing issue that @Duckhunt had was a fluke......or I just got lucky on the 1st try but now that we know sensor spacing it should be easy. I think between Duckhunt's speedo & my final seal issues we've got the bugs worked out. It really makes the P5 more fun without losing the utilitarian gearing. If you have any questions feel free to contact me.

Oh I definitely will be contacting y’all when I get ready. Could you or @Duckhunt maybe get a in cab video or it? I’m lucky enough I can bring my sxs to work and work on it. But for a big enough project like that I need to wait until he takes his summer vacation. I don’t want to tear it down during right now during hunting season or I would do it over the holidays. Also if I can prolly get our machine shop to make me some spacers if .100 is the magical number I can get a few made up.

 

[906UP]

Mine is put up for the winter.....its snowmobile season UP here

 

[Duckhunt]

Mine is put up for the winter.....its snowmobile season UP here

LOL same here! Unless you want a video of me pulling my ice fishing sled 10-15mph across a frozen lake till there's too much snow for that, which could be any day now! Kidding, but also dead serious... Next spring I'm your guy!

@Spellmajr for the spacer I'm curious what the exact OD of the 25 tooth gear is. If you have a micrometer or even caliper measure it up! Realistically you take the difference of the old and new gear's radiuses (.5 diameter) and use that to be nuts on. Won't be exact because odd tooth count gear doesn't have a tooth 180 degrees across but add a few .001" should be close. Obviously some tolerance.