Speed transmission

[Nikal]

Since the transmission is a hot topic lately, I figured I would start this discussion over in the powertrain section where is should be.

For those who did not know the Speed UTV transmission design was done by Albins in Australia, and Weddle consulted Speed UTV. Weddle will also be the authorized repair facility for Speed UTV.

Due to the production transmission gear failures before and at the King of the Hammers. Sean with Weddle had posted some info and what he knows about what was happening.

This was from Sean Ritchie at Weddle.

The trans issue discovered last week was a surprise to all of us, but was not due to poor design, nor from shifting them. Since Robby said it in his video last night, I guess I can elaborate:

The housings were not the issue of the failure, the gear broke first, which wedged bits of gear teeth through the other gears and had enough force to push the shafts apart, splitting the cases. Robby saying they are adding material to the cases to strengthen them is really just an added benefit to prevent the cases from splitting like that and ruining the whole trans. Gears wear and break over time and use, when they do finally let go, it is cheaper to not have to replace the entire case as we can just replace what is broken and repair the gearbox.

The gear breakage sucks. Robby called me immediately after the first one broke last week and we discussed. We had hoped it was a fluke failure based on what that transmission was subjected to. This was not a fault that Speed or Weddle could have known about on the variety of transmissions and diffs we have inspected since they came off the assembly line. The issue only became evident once subjected to that level of use. Real world testing will always find the weak links.

The good news is that it is somewhat of an easy fix, other than having to wait a bit longer for revised parts.

I will stand by that anyone who damages this trans because of shifting, is purely on the driver of the vehicle. It is a great feature of the gearbox, but requires knowledge of how to properly operate.

 

[Nikal]

Sean was asked about Speed gear sizes and are they undersized and why they failed?

“Answer: Gears break when they aren't heat treated properly, or not to spec, or with improper material. I have not seen the heat treat spec sheet on these, nor have I seen the broken gears back here yet (should see them this week), so I cannot say what the exact issue is just yet.

The gears in these Speed UTV's are twice the size of any other UTV gearbox on the market. There was no reason for them to break or wear out with the amount of miles and use they have on them. The highest mileage gearbox I have seen from them had about 6000 miles on it, and the gears looked great.”

Here was Sean’s response to another question about the gears & case.

“For what it's worth, I have not performed a full Weddle race prep on any Speed trans like we do for the others (Polaris, Can-Am, Arctic Cat, etc.). I wanted to wait and see how the factory made parts held up without our involvement. I don't believe our race prep process (deburring, shotpeen, REM polish) would have made any difference on these.”

 

[Nikal]

Now for those who have not seen the inside of the Speed UTV trans and front differential. Here are some pre production transmissions that were torn down for inspection. This transmission case has a was cut away section to better see the gear stacks inside.







Here you can see the section of the case cut away to better see the gear stacks.



In this picture you can see the hand pulling up on the “Dog Gear”. That’s what locks the selected gear in place, but allows you to shift on the fly. The lower gear on that same stack has another “Dog” that you can see.



Just to the right of the hand, In that stack you can see the “Dog” and how the two pieces are separated.

 

[Nikal]

Here are two pictures of the front differential.


This is the ring gear inside the differential. This strait cut gear is why the front has a gear noise. Robby said they worked on trying to quiet it down as much as possible.


This is looking at the inside of one side of the front differential bulk head.

 

[Nikal]

Sean with Weddle has said several times that the Speed transmission is very robust and the gears are the largest compared to the other top UTV transmissions.

Here is a few pictures of the different brands transmissions.

Speed UTV



Polaris RZR designed and manufactured by Team Industries. It’s been said the Arctic Cat XX is almost identical as it too was manufactured by Team Ind.




Here is the Can Am X3 trans. I believe this was design and is manufactured via Can Am/BRP. Photos courtesy of Cryo Heat.

 

[Fighting Chicken 583]

Since the transmission is a hot topic lately, I figured I would start this discussion over in the powertrain section where is should be.

For those who did not know the Speed UTV transmission design was done by Albins in Australia, and Weddle consulted Speed UTV. Weddle will also be the authorized repair facility for Speed UTV.

Due to the production transmission gear failures before and at the King of the Hammers. Sean with Weddle had posted some info and what he knows about what was happening.

This was from Sean Ritchie at Weddle.

The trans issue discovered last week was a surprise to all of us, but was not due to poor design, nor from shifting them. Since Robby said it in his video last night, I guess I can elaborate:

The housings were not the issue of the failure, the gear broke first, which wedged bits of gear teeth through the other gears and had enough force to push the shafts apart, splitting the cases. Robby saying they are adding material to the cases to strengthen them is really just an added benefit to prevent the cases from splitting like that and ruining the whole trans. Gears wear and break over time and use, when they do finally let go, it is cheaper to not have to replace the entire case as we can just replace what is broken and repair the gearbox.

The gear breakage sucks. Robby called me immediately after the first one broke last week and we discussed. We had hoped it was a fluke failure based on what that transmission was subjected to. This was not a fault that Speed or Weddle could have known about on the variety of transmissions and diffs we have inspected since they came off the assembly line. The issue only became evident once subjected to that level of use. Real world testing will always find the weak links.

The good news is that it is somewhat of an easy fix, other than having to wait a bit longer for revised parts.

I will stand by that anyone who damages this trans because of shifting, is purely on the driver of the vehicle. It is a great feature of the gearbox, but requires knowledge of how to properly operate.

@Nikal you stated "Due to the production transmission gear failures before and at the King of the Hammers".

I was only aware of the one that failed at KOH, was there another? Did I miss something?

 

[Nikal]

@Nikal you stated "Due to the production transmission gear failures before and at the King of the Hammers".

I was only aware of the one that failed at KOH, was there another? Did I miss something?

It was said the week leading up to KOTH they had a trans fail. I think it was in the #18 car? I believe this is the one Weddle mentions looking over and thinking maybe it was just a one off fluke. At the time they did not think they had a gear heat treatment problem. Then when they went to KOTH and broke another prerunning, they knew there was an issue. I could be mistaken but that’s what I heard. I hope to get @Sean@Weddle to come on here and share some more.

 

[Fighting Chicken 583]

It was said the week leading up to KOTH they had a trans fail. I think it was in the #18 car? I believe this is the one Weddle mentions looking over and thinking maybe it was just a one off fluke. At the time they did not think they had a gear heat treatment problem. Then when they went to KOTH and broke another prerunning, they knew there was an issue. I could be mistaken but that’s what I heard. I hope to get @Sean@Weddle to come on here and share some more.

Hey bud, thanks for the update. I really appreciate that. I didn't hear about the 18 car, so hopefully Sean can clarify. Thanks again.

Oh, and thanks for starting this thread. Cuz we all know how hot this topic is.

 

[CampfiresNbrews]

Hey bud, thanks for the update. I really appreciate that. I didn't hear about the 18 car, so hopefully Sean can clarify. Thanks again.

Oh, and thanks for starting this thread. Cuz we all know how hot this topic is.

During RG’s last presentation he stated that they had identified some issues on Wednesday before the Hammers and had made changes to the cases (thicker) and that they have already begun production of those.

Then later in that same show he says that they took the transmission out of car #19 and put it into car #18. So I assume that’s the one that broke on Wednesday before the event.

 

[Sean@Weddle]

They broke one climbing hills and rocks in Havasu the week before the 1st weekend of hammers. We figured it was a fluke breakage based on what the car was doing when it broke.

Another one broke in the rocks pre-running on the 1st weekend. That's when we knew there was a likely issue with the heat treat on the gears.

The one I put back together before the 1st weekend was the third one that broke on Thursday in the UTV rock race and was airlifted out.

I don't think these would break under 95% of how they are used and driven. There are more than a few that have plenty of miles on them with no issues. Racing tends to find the weak links. Speed is taking the smart, proactive approach to replace these with updated units rather then send them out on customer cars where a select few could fail under hard use.

 

[Nikal]

They broke one climbing hills and rocks in Havasu the week before the 1st weekend of hammers. We figured it was a fluke breakage based on what the car was doing when it broke.

Another one broke in the rocks pre-running on the 1st weekend. That's when we knew there was a likely issue with the heat treat on the gears.

The one I put back together before the 1st weekend was the third one that broke on Thursday in the UTV rock race and was airlifted out.

I don't think these would break under 95% of how they are used and driven. There are more than a few that have plenty of miles on them with no issues. Racing tends to find the weak links. Speed is taking the smart, proactive approach to replace these with updated units rather then send them out on customer cars where a select few could fail under hard use.

Sean thank you for coming on here and sharing your info. I find it valuable and very appreciated. Any more information you can share is going to be appreciated. Not just on the gear issue, but things you like or think was different on the Speed drivetrain vs the other brands. Or how Weddle’s consulting Speed UTV has made the Speed trans different or better. (Not trying to knock the other brands, but you get to see the good & bad in them all)

I’m sure there’s more than just me who is knowledge hungry to learn as much as we can. That’s part of what has made this Speed UTV journey so fun, is all that has been shared and how much we are able to learn before ever starting the machine.

I always look forward to seeing the improvements you guys have made to the different brands trans & difs. Like the new stuff you’re doing with the XX front dif. Hearing it’s like a “Super Dif”. 4 spider gears maybe?

 

[BajaOrBust]

I’d be curious to know why they chose straight cut gears for the ring gear of the front diff.

 

[Nikal]

I’d be curious to know why they chose straight cut gears for the ring gear of the front diff.

I’m sure @Sean@Weddle would know?

I think some of it is due to costs of making the gears. I know the RZR & XX Team Ind. front diff’s use a straight cut gear like what Speed is using. I have not seen the Can Am ring gear to know what they use?

I also know Speed front drive is manually engaged. Not sure how that might work or could effect the gear design choice?

 

[Ebes471]

Sean thank you for coming on here and sharing your info. I find it valuable and very appreciated. Any more information you can share is going to be appreciated. Not just on the gear issue, but things you like or think was different on the Speed drivetrain vs the other brands. Or how Weddle’s consulting Speed UTV has made the Speed trans different or better. (Not trying to knock the other brands, but you get to see the good & bad in them all)

I’m sure there’s more than just me who is knowledge hungry to learn as much as we can. That’s part of what has made this Speed UTV journey so fun, is all that has been shared and how much we are able to learn before ever starting the machine.

I always look forward to seeing the improvements you guys have made to the different brands trans & difs. Like the new stuff you’re doing with the XX front dif. Hearing it’s like a “Super Dif”. 4 spider gears maybe?

Well said Nikal! It is awesome that Sean took time to offer an explanation. I feel like this is another reason Speed is different from the competition.

 

[PropDr]

I’d be curious to know why they chose straight cut gears for the ring gear of the front diff.

That is a question I had for a long time; I would love an explanation from the speed engineers...
Note: pinion gear thrust bearing loading increases with spiral bevel gears.

 

[Nikal]

Not looking to start a bash the other brands. But I thought I would share a friends UTV trans from a month ago, as they can all fail. And he’s not a hard runner either.

It started as a clicking, which he thought was a cv click and was attempting to limp it back to camp. He finally heard a grind & pop, which then sounded like gears binding up.

The root cause was a bearing failure which then bearing material went through multiple gears and damaged the case.

 

[PropDr]

Not looking to start a bash the other brands. But I thought I would share a friends UTV trans from a month ago, as they can all fail. And he’s not a hard runner either.

It started as a clicking, which he thought was a cv click and was attempting to limp it back to camp. He finally heard a grind & pop, which then sounded like gears binding up.

The root cause was a bearing failure which then bearing material went through multiple gears and damaged the case.

View attachment 347

Just a side note addressing gear boxes.
A F1 gearbox can withstand tremendous loads, as long as the loads travel as designed.
One side impact on a rear wheel (and these cars pull high G's in turns) and the gearbox is trash.

 

[Robhull91]

Straight cut gears are strong, not as much surface contact as helical but also don’t have the extreme axial load helical does. however, more noisier. if you can get around the noise you will have a stronger gear set as it pertains to adjacent components, not speaking just tooth to tooth contact. I’m happy they chose straight cut.

 

[Truck-it]

I've riden in the car on and off road. It's definitely more noticeable on pavement. It doesn't bother me but I can guarantee the hwy warriors are going to bitch about it when they get their cars.

Straight cut gears are strong, not as much surface contact as helical but also don’t have the extreme axial load helical does. however, more noisier. if you can get around the noise you will have a stronger gear set as it pertains to adjacent components, not speaking just tooth to tooth contact. I’m happy they chose straight cut.

 

[Sean@Weddle]

The straight cut gear in the front diff is a mix of strength and cost effectiveness. They are effectively a "stamped" out forged gear. This allows them to create a inner "wall" on the inside of the ring gear and pinion teeth, which greatly helps to strengthen the tooth and prevent breakage. The material used for this method is quite a bit cheaper than conventional gear materials.

The downside is that you cannot use high quality gear materials as they are too hard to forge, so you need to use softer material. They do also make more noise than a typical spiral bevel type R&P. Team industries have been using these on their front diffs up until the new Pro-R units (which are now spiral bevel R&P's). They do work just fine under 99% of use. Desert racing and abusive driving (rock bouncing for example) are really the only thing that hurts these style of gears.

For what it's worth, I am really quite impressed with the front diff gears in these Speed units. We will see how well they hold up over time, but they appear much better than others.

And yes, we do now have a 4-spider gear super diff for the Wildcat XX front diff, that one is my baby.