Attn. Frank Merkl!!!

Hey Frank been having some issues with clutches in my racing trans (C6). It isn't really a big deal but got me wondering why. The trans has 5 red altos and kolene steels in all clutch packs and all clearances were dead in the middle of the specs you suggested but the center three clutchs in the forward and direct are wearing out the inside and cupping the steels. This is over the course of 2 fulls seasons with 40-50 passes, the local trans shop says it's just a function of the extreme pressures applied with the manual valvebody. The VB was a TCI full manual reverse pattern deal but will be going to a transbrake setup soon, this was with a ~700hp engine and we have upgraded the engine program this year. Do I just need to replace them on teardown every year as part of routine maintenence or is there a fix.

Does anybody have an answer? Everything is in Frank's specs.

Did you try and PM Frank??

Frank should be gearing up for crop season right now so I am sure he is busy. I would try the PM thingy because it usually sends them an email.

Frank is a dedicated farmer...a man outstanding in his field

ha ha ha thats funny

that is not unusual for a clutch to wear the center steels an clutches first. one of the reason is it can push the fuild out of the pack fast enought so the center is last to apply so overheating and cupping. one fix is to drill holes around the clutch drum to let fluid out faster

I have not pm'd him i figured he would be busy this time of year,
though. Can I drill the drainholes in the direct and forward drums both?

sounds to me more a problem with the VB , the cupping is from overheating , check the line pressure ,you should have at least 150 psi at 2500rpm
Frank

PS just gotin off the tractor for supper , then after supper I have to go fix wiring on a Irrigation pivot that looks like a raccooon eat!!!!
Frank

Frank Merkl wrote:sounds to me more a problem with the VB , the cupping is from overheating , check the line pressure ,you should have at least 150 psi at 2500rpm
Frank

X2

You should not be seeing any wear on the forward clutch. That clutch is engaged in all forward gears meaning it should be locked up. If it is showing wear like you discribe you have a problem of either not enough capacity or not enough pressure to keep the clutches from slipping. I'd say it not enough pressure.

Regarding drilling drums for oil release. I would tread carefully. The forward is locked up as soon as you shift into a forward gear and stays that way in all forward gears so there is NO reason to drill the drum.

The Hi/Rev clutch drum is disengaged in 1st and 2nd, when you shift to 3rd the intermediate band is released and the Hi/Rev clutch is applied. There is a timing issue here and too much over lap can cause a bind, and not enough overlap can cause a flare.

Drilling the drum will release fluid quicker so the clutch can engage quicker - that is the theory. In reality if the discs have some type of pattern (grooving) on them the oil will be released (moved out of the way) when the clutch applies. If there is no grooving (discs are smooth) then you can end up with them hydroplaning and oil release holes can help. Another way is to have a very, very fast apply with a larger feed and more pressure that basically squishes the oil out of the way. Only reason to use smooth discs is to try and gain more surface area for more capacity.

Now when in 1st gear the Hi/rev drum is spun backwards at a fairly high rate. If you drill the drum you will have less oil to cool and lubricate and more friction. Do a good enough job and you will weld the clutches and steels together... ask me how I know... learned this the hard way twenty some years ago. After two failures, the second welding the clutches together I put the drum with the four 3/8" holes on the shelf and put a stock one in and no more problem.

BTW no need for Kolene steels in the forward clutch, save you money. Raybestos has a new HP clutch material out. A lot cheaper than the blue plates and would be an upgrade from the Alto Red. I have used it once so far in a 700R4, not much to say, but if it was me I'd use that and regular steels, the thicker, the better.

Steve

Thanks from everyone I do not know line pressure and trans is torn apart to be rollerized and clutchs replaced. The vb is tci manual reverse and will be changing it to a break unit. The tranny has shifted flawlessly and also has a E lever with an R code servo with the oring groove turned down.

Frank did you sell all your brakes?

sold out
Frank

Frank Merkl wrote:sold out
Frank

glad i got mine

Looks like probably gonna go with a unit from Broader any feedback?

bigblok2000ranger wrote:Looks like probably gonna go with a unit from Broader any feedback?

i have one from jay at broader, works good for me , and has an external solenoid.fast release. trans clutches always looked good, ran 9.40s in a 3250 pd car ,

Just talked with Jay a little bit ago and discuss a few things with him, he thinks perhaps the clearances I had may have not been right with the TCI valvebody or may have had excessive pressure. I did not follow the instructions for the suggested clearances that came with the valvebody.

bigblok2000ranger wrote:Just talked with Jay a little bit ago and discuss a few things with him, he thinks perhaps the clearances I had may have not been right with the TCI valvebody or may have had excessive pressure. I did not follow the instructions for the suggested clearances that came with the valvebody.

i would say to tight of clearance or not enough pressure . or both , jays brake is user friendly , i used an E lever ,wide band and a good servo with a stock spring.

I have an E lever R code servo and the stiffer spring that came with the servo but do still have the stock spring on the shelf if that will work better.

bigblok2000ranger wrote:I have an E lever R code servo and the stiffer spring that came with the servo but do still have the stock spring on the shelf if that will work better.

my stock spring was stiffer than the one that came with my sonax sevo.

I think mine was stiffer than either of the ones that came with it too I kinda assumed there was a reason they included the springs though but we know what that gets you. Lol