C4 verses the OC12

[fogtender]

I hear lots of complaints about the C4 transmission in the Imp and that the OC12 is suppose to be better.

Can anyone tell me what is "Suppose" to be the bad part of the C4, I have put on a lot of miles breaking trail and in general, using it in the wilderness and haven't really had any problems. Roughwoods did break an axle on his standard track, but that may have been from prior abuse of some kind before he bought it. I have had mine for about three years now and made maybe around the upward side of a couple of thousand miles in all (about 950 hours on it). That has been pulling some heavy loads and breaking trails though somewhat deep snow, not like in some of the members areas where they get six feet in a day, but I would have no fear issues about going though that stuff with my widetrack.

Anyway, if you know of issues other than just "Bad" would like to hear them to see if they are something that I need to check on.

Thanks!

 

[mtntopper]

I would say the differences in the C4 and OC12 is like a comparing the Ford F150 to the F350. They are designed for different applications. If you expect the F150 to haul, tow and work as hard as the F350, you will soon be disappointed. But for the design and if used properly the F150 will live a long life if taken care of properly. The F350 is made to do the bigger jobs, haul the heavier loads and live longer while doing those jobs much like an OC12 rear end in a Spryte or LMC 1200. The C4 will last a long time in the smaller, lighter, and less powerful Imp if taken care of and not abused beyond its design and purpose. It is still capable of hauling loads, pulling a small drag and other tasks with in its design abilities. The OC 12 may even be over kill for the Spryte and LMC 1200 but that is why their reputation of being better than the C4 is talked about so much on the forum. The C4 is still a very good rear end and is much lighter in weight than the OC12 and that is one of its big pluses and reasons it is used in the smaller Imp and some other snow cat applications. Thiokol built some great snow cats and the Imp is one of the best ever designed and is a very capable smaller snow cat to do most jobs.

Just remember, that bigger jobs require bigger tools and a snow cat is also tool to do a job.........

 

[fogtender]

Just remember, that bigger jobs require bigger tools and a snow cat is also tool to do a job.........

I would pretty much agree with your version, but just wanted to know if there was something that was "typically" wrong with them, other than they are "suppose" to be bad.

Kinda like my view of Fords in General... I quit badmouthing Fords after I found out that I could make a good living fixing them...

 

[mtntopper]

Kinda like my view of Fords in General... I quit badmouthing Fords after I found out that I could make a good living fixing them...

I own both a F250 and F350 so now the C4 sucks and is not worth its weight in a way shape or form.... How do you like that?

Actually, there is nothing wrong with the C4 if used as it was designed and intended. Just don't expect it to work like an OC12. They require more effort to turn and just are not as forgiving as the OC12 but they work in an Imp well.

 

[mtncrawler]

I think they work better in a 1200 than an Imp. The 3.33:1 reduction in the drop axles more than makes up for the larger track footprint.

 

[fogtender]

I own both a F250 and F350 so now the C4 sucks and is not worth its weight in a way shape or form.... How do you like that?

Ouch, you are into self abuse with two Fords, I only have one C4!

Actually, there is nothing wrong with the C4 if used as it was designed and intended. Just don't expect it to work like an OC12. They require more effort to turn and just are not as forgiving as the OC12 but they work in an Imp well.

I haven't had any real issues with my C4, I just hear all the horror stories without the details of why the horror. I know that a few have broken the axles, but I don't know where or how they were used and/or abused. You can fracture an axle and get a bit farther down the trail on it before it, or sell it before it has a total failure, which seems to be the case on one that I know of. He wasn't doing anything I hadn't done with mine, but it broke with hardly any time on it by him.

 

[mtncrawler]

Where are you hearing all these horror stories about OC-4's? I see alot of chatter on this web site that OC-12 is the only way to go, mostly by people who haven't used one. OC-12 is stronger, No doubt. Strong enough to be used in full size ski area groomers like the LMC 2100. If you need that level of performance get one for sure. If not an OC-4 equipted machine will work fine if you educate youself on how to operate it and keep it adjusted properly. I think axles get broken or weakened by holding a turn or sidehill more than a few seconds without letting the bands oil.

 

[fogtender]

Where are you hearing all these horror stories about OC-4's? I see alot of chatter on this web site that OC-12 is the only way to go, mostly by people who haven't used one. OC-12 is stronger, No doubt. Strong enough to be used in full size ski area groomers like the LMC 2100. If you need that level of performance get one for sure. If not an OC-4 equipted machine will work fine if you educate youself on how to operate it and keep it adjusted properly. I think axles get broken or weakened by holding a turn or sidehill more than a few seconds without letting the bands oil.

Well I have a few thousand miles that I put on mine over the last three years, and it seems to preform fine. Thanks for you input!

 

[fogtender]

Where are you hearing all these horror stories about OC-4's? I see alot of chatter on this web site that OC-12 is the only way to go, mostly by people who haven't used one. OC-12 is stronger, No doubt. Strong enough to be used in full size ski area groomers like the LMC 2100. If you need that level of performance get one for sure. If not an OC-4 equipted machine will work fine if you educate youself on how to operate it and keep it adjusted properly. I think axles get broken or weakened by holding a turn or sidehill more than a few seconds without letting the bands oil.

Well I have a few thousand miles that I put on mine over the last three years, and it seems to preform fine. Thanks for you input!

 

[IMP]

Can you elaborate a little more on what not to do to a c4. I dont understand what you said about side hilling and letting the bands oil?

 

[mtntopper]

I think they work better in a 1200 than an Imp. The 3.33:1 reduction in the drop axles more than makes up for the larger track footprint.

What I am saying is the OC12 is a better a choice in a Spryte because it is built heavier and will handle more load than the C4 if you are working the snow cat hard which was the purpose and use of most Sprytes. I would agree, in an Imp they seem to be much too high geared for my type of snow conditions but the C4 may work well at lower elevations and with different snow conditions.

Does the drop axle reduction gearing in the Spryte make the C4 more responsive in turns and braking action than in the Imp?

 

[mtntopper]

Can you elaborate a little more on what not to do to a c4. I dont understand what you said about side hilling and letting the bands oil?

The design criteria for making turns with this type of brake band is to pull the brake levers and release quickly to make your turns. This may require pulling and releasing several times to make a single turn. You should never just pull and hold the lever for any long length of time, if possible just quick multiple pulls until the turn is completed. This will allow the bands to stay cooler and lubricate between each pull and prevents premature wear.

 

[mtncrawler]

The design criteria for making turns with this type of brake band is to pull the brake levers and release quickly to make your turns. This may require pulling and releasing several times to make a single turn. You should never just pull and hold the lever for any long length of time, if possible just quick multiple pulls until the turn is completed. This will allow the bands to stay cooler and lubricate between each pull and prevents premature wear.

Pay attention this is how to operate your snowcat especially if you have an OC-4 driven unit. Holding tight for extended periods over stresses axles.

 

[mtncrawler]

my type of snow conditions but the C4 may work well at lower elevations and with different snow conditions.

Does the drop axle reduction gearing in the Spryte make the C4 more responsive in turns and braking action than in the Imp?

In my experience lower elevations with thick, wet snow is a real killer for OC-4 Sprytes. Steering the tracks in deep mucky snow overheats the bands and causes loss of steering. The differential section of the OC-4 only holds about 1 gallon of oil compared to 5 in the OC-12. And I've never seen a diff. cooler on a A-Spryte like was factory on the LMC 1200. From what I've seen A-Sprytes shine at high altitude on cold powder snow where turning is easy and lightweight/footprint size keeps the machine from sinking so bad.
A-Spryte reductions do not make the machine turn or maneuver like a 1404 Imp. They do soften the strain on the OC-4 though and make it possible to run the same footprint as the rest of the 1200 series only with a lot less weight. A-Spryte won't turn with a 1404 but will sure outclimb it. (as tested in powder near Breckenridge at 10,000')

 

[Bulldog1401]

Great info. Thanks!!

 

[IMP]

The design criteria for making turns with this type of brake band is to pull the brake levers and release quickly to make your turns. This may require pulling and releasing several times to make a single turn. You should never just pull and hold the lever for any long length of time, if possible just quick multiple pulls until the turn is completed. This will allow the bands to stay cooler and lubricate between each pull and prevents premature wear.

That is how I have been turning thanks for confirming that. I didnt think about the oil cooling effect but I could "feel" the stress of a long steady steering pull.
I notice if I decellerate slightly while turning I get a quick sharp turn? can you explain that?