Hi guys, a penny for your thoughts... My Rolla has a 7K fitted to what I'm assuming to be a standard 5 speed out of a Ke30. Bellhousing is cast onto the body of the box. When I first purchased this vehicle, it was running a 7K flywheel and heavy duty clutch. As I soon discovered, I was breaking a clutch cable on average once a month. This was because the fork had little or no adjustment, due to the fact that the fork was pushed right against the back of the spline due to the height of the 7K clutch and flywheel. I proceeded to change back to the smaller 3K flywheel and standard clutch. Since then the vehicle has considerable vibration on acceleration and decel, most notable around the 2-4 thousand rpm mark. my question is this... Is the 7K running a counterbalnced crankshaft, and hence the lighter flywheel has thrown the whole thing out of balance? Should I just go and buy the 7K box to go with the motor? If so will I have shorten the tailshaft or any other mods to fit? The vibration is killing me!!!

I was under the impression you could use a 7k flywheel on a 5k, as I was looking for one, but really have no idea weather it can be done or not.

 

If the 7k crank was counter balanced, you may be able to get a 3/4k flywheel balance to match it.

 

There is a guy on rollaclub who has a 7k with k40/50, he spend like $450 or something stupid on a custom clutch plate that went on a 7k FW, but matched the k40/50 input spline.

 

If you want a KR42R gearbox, then budget for around $800-$900 for the box alone. You then need to do a hydro clutch convo, as these boxes are are hydro, not cable. You will also need the out put spline for the back of the GB, to be modded onto a ke30/55 tail shaft. So expect ove $1k to convert to this GB. :)

 

I can make another suggestion for you:

Have a look through my how to fit a W50 GB to a K series engine thread.

If you were to get yourself a W50 or W40 and tail shaft yoke from a celica or corona, a KM20 liteace bellhousing, clutch fork, and TOB retainer, then use the 7k FW with a stock PBR KR42R clutch pack ($180) not in heavy duty (not really needed anyway!) then you're all good to go.

So to do this option price are below:

KM20 BH, clutch fork, retainer - $275 (I can get this for you from a local wreckers, but its that price as he won't seperate from the GB, so you can get that too, but its for column shift)

W40/50 and tailshaft yoke - $50 to $200 depending were you get it. I paid $50 for mine (thanks James :cool: )

7k flywheel - you've already got it

KR42R clutch kit - PBR stock kit - $180, RPM heavy duty - $230'ish can't remeber

**Note, a 7k clutch matches up perfect to a W40/50 box!! :P

 

So total of $505 to $705.

 

Lemme know if you want more info.

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Edited May 24, 200818 yr by Sbox

My 2 cents worth would be that the lighter clutch is shuddering in this rev range. Go the heavier clutch and a hydraulic master and slave setup.

Taz Rx which year model did this box come out of? I had a look on the FAQ's and it says that the w50 is an extremely large box (supra 5 speed) and that I will need some serious tunnel mods to fit it?? other thyan that it sounds like my best option, although I just had 4 grands worth of interior done and I'm not looking forward to cutting sexy new holes in my new carpet hehe

Don't reckon It'l need tunnel modding for a w50. W55, 58 etc yeah.

 

W50 is out of an RA40 celica....that I know of, probably more.

W40 is from a corona.

Don't reckon It'l need tunnel modding for a w50. W55, 58 etc yeah.

 

W50 is out of an RA40 celica....that I know of, probably more.

W40 is from a corona.

The 7K flywheel will fit into the K series bellhousing, but only with a huge amount of mods. The inside of the K series BH must be ground away extensively, and even then the 7K clutch is too large and causes the TOB to be pushed back against the base of the spline. The result is no adjustment available and snapped clutch cables. Although I never had vibration when this setup was in the vehicle, again it just kept snapping cables. The million dollar question I suppose is.... Is the KM20 bellhousing and bigger internally than the standard K series bellhousing?

The million dollar question I suppose is.... Is the KM20 bellhousing and bigger internally than the standard K series bellhousing?

 

Have both at home so I can check.

 

You can always use a KM20 liteace flywheel and clutch, and BH!! with a W50. Clutch spline is the same and I can garentee a KM20 flywheel and pressure plate will fit inside a KM20 BH. :yes: funny that!!

Have both at home so I can check.

 

You can always use a KM20 liteace flywheel and clutch, and BH!! with a W50. Clutch spline is the same and I can garentee a KM20 flywheel and pressure plate will fit inside a KM20 BH. :yes: funny that!!

if thats what it will take to fix this issue then so be it... KM20 liteace..which year model would that be? I only ask as most wreckers when you give them a model number they have no idea what you are talking about

Think they're around 80, 81, 82'ish. Which ever one has a 200mm/29mm/19T clutch kit. :yes:

Taz Rx which year model did this box come out of? I had a look on the FAQ's and it says that the w50 is an extremely large box (supra 5 speed) and that I will need some serious tunnel mods to fit it?? other thyan that it sounds like my best option, although I just had 4 grands worth of interior done and I'm not looking forward to cutting sexy new holes in my new carpet hehe

 

picsorban :nod:

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Edited May 24, 200818 yr by Sbox

There is a guy on rollaclub who has a 7k with k40/50, he spend like $450 or something stupid on a custom clutch plate that went on a 7k FW, but matched the k40/50 input spline.

 

That was me! :yes: :yes: :hmm: At least it saved alot of mucking around. Unfortunately it also emptied the wallet too!

Edited July 9, 200719 yr by 78_7kRolla

You will snap cables, the cable is only for the light 3k-4k clutch. 5k engine gearbox setups require the hydraulic master and slave (so yours definitely would) although Chris from Chris and Liz was telling me about an extra pivot setup he had thought of. I don't know how far he got with it, but it sounded like a reasonably simple solution. Add a lever and double your application of force, with the original cable and no extra strain on it. Ask him as he may have fleshed it out and he knows his way round a rolla. If you had an adjustment issue in the first place the fingers on the pressure plate would have worn out from having the TOB running on it all the time, this has not sounded like a clearance issue from the start. Merely using something for a job it was never meant to do.

Yes sbox the fingers on the virtually new plate were indeed lifted and worn. Sorry I probably should have mentioned this before. There was a trick i used to use that was actually specified by OS Giken for fitment of all their twin plate clutches whereby you would actually grind off part of the TOB stopper which covered the rear section of the spline but I can't remember how much meat was on that section. I guess its time to bite the bullet and pull the box out...

Hi guys, a penny for your thoughts... My Rolla has a 7K fitted to what I'm assuming to be a standard 5 speed out of a Ke30. Bellhousing is cast onto the body of the box.

 

Hi.

My race car had a 5k with a lightened 4k flywheel and standard (cable) 4k clutch. The box was a k50.

It all went together perfectly with no modifications. The standard clutch and box survived many hill climbes. sprints and track days.

I changed to a modified 7k and again used the lightened 4k flywheel and a new standard clutch but had it all ( front pulley, crank, flywheel, clutch pressure plate) balanced when I built the engine.

It all went together with the same old k50 box without any big problems and no unusual vibrations.

Hi guys, a penny for your thoughts... My Rolla has a 7K fitted to what I'm assuming to be a standard 5 speed out of a Ke30. Bellhousing is cast onto the body of the box.

 

Hi.

My race car had a 5k with a lightened 4k flywheel and standard (cable) 4k clutch. The box was a k50.

It all went together perfectly with no modifications. The standard clutch and box survived many hill climbes. sprints and track days.

I changed to a modified 7k and again used the lightened 4k flywheel and a new standard clutch but had it all ( front pulley, crank, flywheel, clutch pressure plate) balanced when I built the engine.

It all went together with the same old k50 box without any big problems and no unusual vibrations.

hi ikon do you recall whether the crankshaft had balance weights on it or not? I am under the impression that due to the larger crank in the 7K that it may have been necessary to externally balance the motor due to lack of room in the sump area.