Knock in gearbox/drivetrain

[ocyrion]

Hi,

I've got a CC GSR with Evo 1 motor, GSR NRBE box, transfer and diff. As of two weeks ago a knock has developed somewhere in the gearbox or drivetrain. The knocking noise speeds up with vehicle/engine speed and is quite loud in second gear and is also present in first, but all other gears from third and up are completely fine. It sounds metallic. The noise is only there under load and disappears off load or when the car is rolling along in neutral. Both the gearbox and transfer are full of oil.

I took it to Techsport and the guy said he'd never heard a GSR or Evo box do that before. I'm thinking it might be a bearing on the shaft which holds 1st/2nd. Has anyone had their gearbox start knocking only in certain gears? What was it?

Before I stick another box in or give up, could it be anything else?

Which Evo gearboxes (if any) are compatible diff ratio wise with the GSR transfer and rear diff?

Thanks

 

[Qik-1.8]

its could be the tail shaft cv joint, but then its should be doing it though all gears

 

[ocyrion]

its could be the tail shaft cv joint, but then its should be doing it though all gears

I got the front passenger side driveshaft greased and rebooted a couple of days before. Yeah it's odd it's only in 1st/2nd. The tailshaft and centre bearing is pretty loose, it clunks away in third on decel. Strange it's only in 1st/2nd. Hey if it is the tailshaft I'd be pretty damn happy ... having trouble finding a replacement box and Techsport told me they can't get bits if I want it reco'ed. The car only has to last me ~7000kms/5 months more since I'm off overseas (isn't everyone).

 

[bazeng]

I'd get it up on a hoist, put it in gear and drive it up on the hoist to trace the noise..

Either that or do it on a dyno.

 

[evo-gsr]

Shit news for you there mate, don't give up and buy that Corolla just yet!! If you need to buy bits for the box, I'm sure MEEK can help you out, I know they rebuild boxes there.....Even give them a call they MAY be able to help you work out what it is, considering they deal with GSR/Evo's everyday....

 

[Gianni]

I had a similar thng in the. Cc fwd box. But just replaced the box

 

[EVO-00X]

First and second gears share the same shift fork and synchro slider and hub. With the amount of failed 2nd gears from miss-shifts in AWD boxes out there, these could be damaged/worn and so could be the springs and keys. I reckon your problem is a good chance of being there. New GSR slider and hub combo is over $300 new from Mitsubishi and then another $150 plus for synchros, springs and keys. Then add labour and bearings and seals and well... it all adds up. Its worth considering rebuilding what you have than to buy another 2nd hand gearbox in various forms of wear.

None of the Evo boxes will be a bolt in replacement to suit your existing GSR transfer + 3.545 rear diff ratio. You will need to do one of 3 things:
1. Repair existing or get another GSR box (obviously)
2. Get an Evo 1/2 gearbox, keep your existing GSR transfer case, but you will need to change your rear diff ratio to Evo 3.909 ratio. Good excuse to buy a mech LSD Evo rear diff
3. Get an Evo 1/2/3 box, keep your existing GSR transfer case and GSR rear diff, but open the gearbox and replace the Evo front diff crownwheel and output pinion with your GSR front diff crownwheel and output pinion.

 

[ocyrion]

First and second gears share the same shift fork and synchro slider and hub. With the amount of failed 2nd gears from miss-shifts in AWD boxes out there, these could be damaged/worn and so could be the springs and keys. I reckon your problem is a good chance of being there. New GSR slider and hub combo is over $300 new from Mitsubishi and then another $150 plus for synchros, springs and keys. Then add labour and bearings and seals and well... it all adds up. Its worth considering rebuilding what you have than to buy another 2nd hand gearbox in various forms of wear.

None of the Evo boxes will be a bolt in replacement to suit your existing GSR transfer + 3.545 rear diff ratio. You will need to do one of 3 things:
1. Repair existing or get another GSR box (obviously)
2. Get an Evo 1/2 gearbox, keep your existing GSR transfer case, but you will need to change your rear diff ratio to Evo 3.909 ratio. Good excuse to buy a mech LSD Evo rear diff
3. Get an Evo 1/2/3 box, keep your existing GSR transfer case and GSR rear diff, but open the gearbox and replace the Evo front diff crownwheel and output pinion with your GSR front diff crownwheel and output pinion.

Wow, awesome helpful response mate ... :thumbsup: :thumbsup: :thumbsup:

I just impulse bought a schmick AE102 Corolla, bit of a betrayal to the Shitsubishi I know :wacko: But I can probably palm it off to my wife or supercharge the bastard :w00t:

I'm probably going to try to source another gearbox ... the mechanic said it's probably a bearing on the shaft or a chipped gear tooth. I'll either flog it with or without a replacement box put in, I haven't decided. I had the box out already to change the clutch but it's fun on the driveway with such low ground clearance.

Are all GSR gearboxes the same diff ratio wise?

 

[Atters_del]

Hi,

I've got a CC GSR with Evo 1 motor, GSR NRBE box, transfer and diff. As of two weeks ago a knock has developed somewhere in the gearbox or drivetrain. The knocking noise speeds up with vehicle/engine speed and is quite loud in second gear and is also present in first, but all other gears from third and up are completely fine. It sounds metallic. The noise is only there under load and disappears off load or when the car is rolling along in neutral. Both the gearbox and transfer are full of oil.

I took it to Techsport and the guy said he'd never heard a GSR or Evo box do that before. I'm thinking it might be a bearing on the shaft which holds 1st/2nd. Has anyone had their gearbox start knocking only in certain gears? What was it?

Before I stick another box in or give up, could it be anything else?

Which Evo gearboxes (if any) are compatible diff ratio wise with the GSR transfer and rear diff?

Thanks

Hey mate I know this is an old thread ... did you ever find out what the problem was??..mines doing the same right now..would love some help diagnosing the problem...was told "chipped tooth on diff" I havent pulled the gearbox out as yet

 

[ocyrion]

I ended up picking up a replacement gearbox. I believe it was a bearing on the 1st/2nd shaft. Originally the noise started in 2nd and then happened on 1st as well. Given those two gears are on the same shaft that's my reason for thinking it was a bearing on that shaft. I would've pulled it apart but someone wanted the broken box.

 

[Atters_del]

I ended up picking up a replacement gearbox. I believe it was a bearing on the 1st/2nd shaft. Originally the noise started in 2nd and then happened on 1st as well. Given those two gears are on the same shaft that's my reason for thinking it was a bearing on that shaft. I would've pulled it apart but someone wanted the broken box.

ok cool...cheers for the reply