Hewalnd Question.

[EMI]

My son and I are rebuilding/repairing/restoring a VanDieman RF88. The question I have about the gearbox is, what type of oil and how often should it be changed, and how much does it hold. It is a Hewland Mk9.

Thanks.

[Frank C]

Good to hear of another FF in the area!

You can download the Hewland MK9 manual from the Hewland site at: Hewland

Craig Taylor's Taylor Race Engineering in Plano, TX has more information in its Tech Documents section: Taylor Race Engineering
Craig and his employees are very helpful and often answer questions on this site.

What are you going to do with the car? If you are going to race at Hallett, contact me.
Frank Chambers ("Frank C")
chambersfw "at" yahoo.com

[Tom Sprecher]

You typically do not just up and change the oil. It gets refilled after you do a gear change. You can not drain all the oil out of the box unless you remove it and turn it over or on end. Since it is an inverted OEM case the drain hole is now located on top. Do not fill to the sight hole as this is WAY too much.

If you do not do any gear changes you must be only racing on the same track, similar tracks or you need some help. Then you will have to crack the back case off or drain it through the shift detent hole. Don't ask how I know how a Mk9 will drain throught this hole unless you want a $4k answer.

Warning: I am not an expert but I have built the Mk9 forwards and backwards and I do mean backwards.

[Brian]

is 1 litre for a gear change, 1.5 litres for a full fill. Normal synthetic 75W90 differential oil is what I use, and Redline light-weight Shockproof is the upgrade from that.

Brian

[JHaydon]

If you do more than one race in a row at the same track, check the oil level at least after every weekend! I found that one out the hard way.

Synthetic gear oil is the hot setup. RedLine "ShockProof" is great stuff. I've used the Super Light with good success (aside from the big leak mentioned above, which had nothing to do with the oil type). More conservative types may opt for the Light weight, but Heavy is definitely overkill for these cars.

I've also seen other brands of synthetic 75W90 hypoid gear oils used successfully. Taylor's site has a page in the Tech section that's all about gear oil.

The oil level is checked at the (left) side plug. With average size fingers, a very unscientific check is to stick your pinky finger in and bend your finger downward. If you just touch the oil, you're OK.

Someone recently posted a photo here of a dipstick with measurements for more precise checks. Take a rod or piece of thin strap (1/2" x 1/8") aluminum, and bend it in a 90 degree angle so that one leg (the "dip") is about 2 - 2.5" long. Scribe a mark 1.875" down from the bend. That's your target: 1.875" below the bottom of the side filler hole. The other end of the stick can be whatever kind of handle you like.

(And don't forget that a litre is MORE than a quart! Most oils are sold in quart containers, so plan on cracking a second bottle -- don't just empty one in there and think you're covered.)

[EMI]

Thanks for the replys. We are going to change it while its laying in the shop floor before we put it back in the car. We have been building and racing shifter karts for years, but this is a new adventure for us, so I'm sure I will be asking alot more questions.

[ZEKESPEED]

If you want to save some Horse Power. Try NEO 18 Weight Gear Oil. We have most of the IRL and Champ Car teams using it. It has been proven. You can effectivly use it all season in a FF/FC, after a gear change filter the oil through a paint filter and reuse, top up when necessary. Contact C&R Racing Inc. 317 293-4100, Peterw@crracing.com Available in quarts, gallons, 5gallon pails and 55gallon drums.

[Frank C]

I am not sure of the configuration in the RF88 (bellhousing and integral oil tank in front of gearbox?), but in the standard MK9 with the VW bellhousing, there is a coupling sleeve between the input shaft and the layshaft that can come loose and drop to the bottom of the differential housing (read inconveniently inaccessible) if the input shaft slides too far forward when the gearbox is separated from the engine. For these gearboxes, one needs to tape or wire the input shaft so it does not move too far. I never had it happen, but I was lucky because I did not realize this could happen the first couple times I had the gearbox out.

If you are going to change oil, it might be a good idea to go ahead and remove the gears to do an inspection of the gears and dog rings. I think it usually is easier to change gears and oil with the gearbox mounted in the car. The torques for the pinion and layshaft nuts are pretty big. Also note that the pinion nut has LEFT HAND threads.
- Frank C

[EMI]

Thanks for the heads up. To answer your earlier question, yes we will be running Hallett in 2006. We got the car just before the last COMMA race and Chris drove it there, but we had a bell housing issue that would keep him from racing. We just got to practice Saturday, and qualify Sunday before it broke.

[JHaydon]

...in the standard MK9 with the VW bellhousing, there is a coupling sleeve between the input shaft and the layshaft that can come loose and drop to the bottom of the differential housing (read inconveniently inaccessible) if the input shaft slides too far forward when the gearbox is separated from the engine. For these gearboxes, one needs to tape or wire the input shaft so it does not move too far.

The drawbolt (which fits inside the layshaft) keeps the input shaft coupled to the layshaft when the gearbox is removed. The drawbolt has to come out when you change gears, and the layshaft gets pulled out of that sleeve, so a gear change really must* be done with the gearbox on the car.

*or else be prepared for a LOT of extra work, including removing one sideplate for access to that coupler.

[Frank C]

Thanks, John. When one is lucky, the friction of the front seal can keep the input shaft from moving too far when the drawbolt has been removed!
- Frank C

[RussMcB]

I am not sure of the configuration in the RF88 (bellhousing and integral oil tank in front of gearbox?), but in the standard MK9 with the VW bellhousing, there is a coupling sleeve between the input shaft and the layshaft that can come loose and drop to the bottom of the differential housing (read inconveniently inaccessible) if the input shaft slides too far forward when the gearbox is separated from the engine. For these gearboxes, one needs to tape or wire the input shaft so it does not move too far. I never had it happen, but I was lucky because I did not realize this could happen the first couple times I had the gearbox out.

Been there, done that. Not fun.

Excellent advice, Frank (and John).

I made a simple cradle to put across the input shaft when the trans was out of the car and the drawbolt wasn't in place.

Only needs to happen once to create a strong impression.

[fawcetteng]

just for those that are searching at apexspeed cause their gearbox doesnt seem to be linked to the engine, i'll say i was caught by the input shaft (clutch shaft) coupler falling off too. had the box out of the car and decided to change the gears. didnt know the purpose of the long screw. took it out, then wrestled the box as i loosened the big nuts on the end of the shafts. the input shaft fell out in the process. put it back in without knowing what i had done. from apexspeed learned that i now had to remove the left side differential plate, pull the differential, and fish out the coupler. of course this coupler wont fit back on the shaft when in place, so then learned i had to remove the bearing locater bolt on the side of the case to remove the layshaft front bearing, which then gave me a big enough hole to slide the coupler through from the rear. Called Taylor to find out which way round the coupler goes - tapered bore with the splines stopping short of the end goes towards the layshaft to help you stab the thing when changing gears. Those Taylor guys are great. My only complaint is they answer my questions too quickly and i have to go back outside into the heat!

[Brian]

lessons to be learned:

never change the gears with the gearbox off the car. If you do, have the gearbox in a stand...

When I lose the connector off the input shaft, I just take the side-plate off the differential. Easy as pie if the box is off the car, and the connector doesn't fall off if the gearbox is on the car...

How do you undo those big nuts if the gearbox is on a bench? I have visions of people standing on it to keep it from moving while several other people keep them from falling off, and more people attack the thing from the rear with a big wrench. Either that or an impact gun, and I just will not use an impact gun on a $4K gearbox...

Brian

[SCOTTY81]

Brian,

With the rear cover off..C-clamp the box to the bench.If you can ,drain the oil and stand it on end
You will want to double gear engage it...
Push in the 1st/Rev shift rail
And also push in the 3rd/4th shift rail.This will engage 2 gears at the same time locking up the box.
Then use a breaker bar to loosen the two nuts.And then pop them back into neutral for the rest of the gear change.

Scotty
Taylor Race Engineering