If the hf2av uses 3 gears to drive the output shaft in high range, how does the underdrive kit work? (1 Viewer)

[Delta VS]

In the event their is noise or an improper mesh. We now have the modified idler. I have not personally installed or tested so I'm still reluctant to make claims on them just yet.

Anyone want a gear set and a modified idler setup?

YES are you just handing them out now?

 

[cruiseroutfit]

YES are you just handing them out now?

We can do something heavily discounted to get them in the hands of folks that will get us some feedback.

 

[Delta VS]

We can do something heavily discounted to get them in the hands of folks that will get us some feedback.

I'll be in touch.

 

[JohnnyOshow22]

In the event their is noise or an improper mesh. We now have the modified idler. I have not personally installed or tested so I'm still reluctant to make claims on them just yet.

Anyone want a gear set and a modified idler setup?

Sorry if I missed it but what exactly does the modified idler gear do for the setup?

 

[cruiseroutfit]

Sorry if I missed it but what exactly does the modified idler gear do for the setup?

Great question, it theoretically has a tooth pitch more closely matching the ratio modified gears. That said there are hundreds (thousands?) of 80's running them noise and trouble Free with the stock idler.

 

[nukegoat]

Correct, as you can see from the chart they only move 2/3 gear tooth counts. These gears have now been on the market for a decade so the longevity and noise concerns are fairly well documented. As I mentioned we do have a modified idler assembly, it's traditionally recommended when the stock setup has extensive wear or gear noise is untolerable. To date we've sold just a few of that idler assembly.

Great question, it theoretically has a tooth pitch more closely matching the ratio modified gears. That said there are hundreds (thousands?) of 80's running them noise and trouble Free with the stock idler.

But it still has the same problem which is a tooth count and tooth geometry that really demands each gear use a different diameter and/or to be translated closer to the input shaft.

It may be fine in practice but I think its worth being clear that its likely worse in strength and operating efficiency than the stock helical gear geometry.

 

[mudgudgeon]

But it still has the same problem which is a tooth count and tooth geometry that really demands each gear use a different diameter and/or to be translated closer to the input shaft.

It may be fine in practice but I think its worth being clear that its likely worse in strength and operating efficiency than the stock helical gear geometry.

Theoretically, this makes sense.
Practically, as Kurt commented, thousands of converted vehicles with no issues.

Not sure how efficiency is going to be impacted?
Strength and noise, sure there's some compromise. But your talking fairly small changes in tooth shape to pick up 2-3 extra teeth on a gear that has 32ish teeth already.
They are a fairly heavy gear set, I think from memory, the gear is 32mm wide. There's still going to be a lot of metal meshing together at each tooth

 

[HDJdreams]

In the event their is noise or an improper mesh. We now have the modified idler. I have not personally installed or tested so I'm still reluctant to make claims on them just yet.

Anyone want a gear set and a modified idler setup?

Kurt - How much is the idler gear? The install?

I have the 1.1:1 and 3:1 gears already. I didn’t realize how noisy it would be on the freeway (In reality no worse than many mud tires, but higher pitch - but my wife really likes to be able to have a conversation and I also have a stock 80 I switch back and forth with so I am frequently reminded how noisy they are.)

I would really like to get some feedback on whether the new idler really makes much of a difference over stock noise wise on the 1.1s.

 

[cruiseroutfit]

Kurt - How much is the idler gear? The install?

I have the 1.1:1 and 3:1 gears already. I didn’t realize how noisy it would be on the freeway (In reality no worse than many mud tires, but higher pitch - but my wife really likes to be able to have a conversation and I also have a stock 80 I switch back and forth with so I am frequently reminded how noisy they are.)

I would really like to get some feedback on whether the new idler really makes much of a difference over stock noise wise on the 1.1s.

I'm in Montana this week on some XOverland business. When I'm back Monday I can look up the idler price and specs as well as which high range gears it's recommended for.

 

[iptman]

Kurt - How much is the idler gear? The install?

I have the 1.1:1 and 3:1 gears already. I didn’t realize how noisy it would be on the freeway (In reality no worse than many mud tires, but higher pitch - but my wife really likes to be able to have a conversation and I also have a stock 80 I switch back and forth with so I am frequently reminded how noisy they are.)

I would really like to get some feedback on whether the new idler really makes much of a difference over stock noise wise on the 1.1s.

You sound like a good test case since you have a stock 80 to test against as a control. I also have both the under drive and lower low gear sets and I didn't notice the additional noise until I took my 80 on a 5 hour trip on the interstate sustaining 70 mph. I'd say it's not terribly offensive but certainly noticeable. It'd be tough to justify pulling the transfer case to swap the idler gear since I had @OTRAMM do this for me. If I could do the work myself though, I'd consider it. Around town and anything under 50mph it's not noticeable. I agree it does sound like worn MT tires. In my case I have brand new KM3s and they're ridiculously quiet for an MT.

 

[cruiseroutfit]

Out of curiosity @HDJdreams & @iptman , were your t-cases fully rebuilt at the time of gear install? New bearings and replace anything with wear?

 

[iptman]

Out of curiosity @HDJdreams & @iptman , were your t-cases fully rebuilt at the time of gear install? New bearings and replace anything with wear?

Yes, in my case. I had a spare t-case I dropped off with Ryan and he used a Terrain Tamer rebuild kit if I recall.

 

[HDJdreams]

Out of curiosity @HDJdreams & @iptman , were your t-cases fully rebuilt at the time of gear install? New bearings and replace anything with wear?

Yeah, full rebuild and gear install done at Cruiser Outfitters a couple months ago

(I am NOT criticizing your work. I am just frustrated that I didn’t realize how noisy they would be and I didn’t realize there was a “quieter” idler option, would have gotten it while I was having everything thing else done.)

Noise (and driving experiences in general) are huge subjectives in general, tough to get a feel for on Mud.

 

[cruiseroutfit]

Yeah, full rebuild and gear install done at Cruiser Outfitters a couple months ago

(I am NOT criticizing your work. I am just frustrated that I didn’t realize how noisy they would be and I didn’t realize there was a “quieter” idler option, would have gotten it while I was having everything thing else done.)

Noise (and driving experiences in general) are huge subjectives in general, tough to get a feel for on Mud.

To be fair we are all theorizing that the gear reduces noise, I just don't know as I've not personally installed one, the few we've sold were in situations hat the stock idler had heavy wear/damage. Companies in Japan and Australia have been selling just the two gear set for a decade or more and to date I've never even seen anyone pairing them in kits with the modified idler, we were the first to order them into the US.

I need to sit down with the modified idler and the high range and low range gear sets to verify which it was actually designed for. It simply can't be for both as they have different tooth counts.

Check out the thread we discussed this in (linked earlier in this thread)

Edit: If we determine the gear is a solid fix for increased gear noise, I'd certainly make it right with you and we would subsequently start offering kits with that gear as an option.

 

[Cruzilla]

When I installed my underdrive gear set from George, I bought the three gear set from him (with Idler gear) I bought all three because I wanted my new gears to mate without having a seasoned (or harder) Idler. I was unaware of the Idler being anything special or modified, perhaps mine is not..?
My transfer does have a bit of wine to it but it is in no way loud, just a slight wine at lower rpm's and not noticeable at high speed on the freeway.

 

[HDJdreams]

To be fair we are all theorizing that the gear reduces noise, I just don't know as I've not personally installed one, the few we've sold were in situations hat the stock idler had heavy wear/damage. Companies in Japan and Australia have been selling just the two gear set for a decade or more and to date I've never even seen anyone pairing them in kits with the modified idler, we were the first to order them into the US.

I need to sit down with the modified idler and the high range and low range gear sets to verify which it was actually designed for. It simply can't be for both as they have different tooth counts.

Staying tuned

 

[cody c]

Kurt, can I make a suggestion:

Get whomever is going to try the modified idler to download one of the decible meter apps on their phone, and then do a few passes (0-60) to get an average or baseline before the idler, then its a bit less subjective of a comparison.

Also, (not directed at anyone in particular) I believe gear design will have been based on the diameter of the gear itself, and the interference of the other gear. The involute curve for the gear face curve should be the same regardless of the other gear, but the spacing and interference of the other gear will affect things as I understand gear design.

In effect, the new input gear is narrower at the ends to allow spacing for the other gears, but they may also be shallower or something.

Im not a gear engineer, just sharing my understanding of how they create the pitches.

The extra noise may be from more clearance (slop) as there may be more gap from the push vs. pull sides because of the added gears, I don't think this is an indication of weakness of the gear compared to stock.

 

[HDJdreams]

Check out the thread we discussed this in (linked earlier in this thread)

It can be really tough to find and follow all the relevant threads and to keep track of actual facts versus idle Internet speculation.

My quick summary on gear noise after 1000 miles: if you spend lots of time on the highway it might bother you (I am surrounded by 80 mph freeways), if you run All Terrains because you don’t like the noise of Mud tires on the highway the gears might bother you.

If you run mud tires and a straight exhaust, you won’t notice the gears

 

[HDJdreams]

Edit: If we determine the gear is a solid fix for increased gear noise, I'd certainly make it right with you and we would subsequently start offering kits with that gear as an option.

I really appreciate it!

New products can be tricky for both the shop and early adopters. I am disappointed, but I certainly feel for you too.

 

[HDJdreams]

Get whomever is going to try the modified idler to download one of the decible meter apps on their phone, and then do a few passes (0-60) to get an average or baseline before the idler, then its a bit less subjective of a comparison.

I have one of those dB apps, it’s tough to isolate the gear noise on dB meter.

It’s very easy to hear the difference, but it lumps everything together. I.e. the gears might not be significantly louder than the 1FZ on the highway, but a significantly more intrusive frequency.

If I get the new idler, I’ll certainly try though. Steady speed 60, 70, 80 mph readings both in OD and in 3rd gear (to change engine rpm) would be more informative than 0-60.