new found weakpoint in drive line

[Adam.Findlay]

well after recently buying a rear wheel drive converted transfer case off kenneth and installing it along side with a evo 8rs plate lsd i seem to have snapped my right halfshaft clean in half. good for a giggle at least. hope to have it sorted by tomorow so will update with some intresting images.
the diff was as solid as a rock though so seems that the non turbo st-r/type v diffs can take it, the half shafts how ever maby not

[foxdie]

What kinda power were you putting through it to do that?

[Kenneth]

You thrashing that transfer case Adam? At least if you thrash it to death, we will get some idea of just how strong they are :P

To reiterate what I said over PM, I am not sure how long the transfer case will last under constant abuse.
You might want to keep an eye on the temperature while playing about to find out how long it takes to overheat. Apparently the design by Mitsi is prone to excessive heat regardless, let alone putting 100% of the torque through the hypoid gear.

[Louis]

NO real way of getting a cooler on it without adding a pump?, poss an electric pump activated by temp, but it would need a take off and return!. Poss take fuid out through drain plug hole to pump, to cooler, and return back in through fill hole. Could be done. Also changing to an amsoil product as they seem to be more heat tolerant without the oil breaking down. can you stick up a pic of where the driveshaft broke, I would have thought the CV or plastic cup would have gone before the metal shaft?. Interesting stuff.

[Kenneth]

I would think you need a pump to move it through the cooler. You might be able to use convection to advantage, but I doubt you would want to rely on that.

You would want to take the fluid from high on the oil line (hot oil) which feeds into the cooler, as it cools it would drop and return to the bottom of the transfer case. I do not think it would be a reliable method for cooling.

You could whack a heat sink onto the casing, but it would be rather vulnerable.

I have no idea how hot it will get, but it is probably worth keeping an eye on until it is known just how much you can do before you start risking damage.

[Adam.Findlay]

You thrashing that transfer case Adam? At least if you thrash it to death, we will get some idea of just how strong they are :P

To reiterate what I said over PM, I am not sure how long the transfer case will last under constant abuse.
You might want to keep an eye on the temperature while playing about to find out how long it takes to overheat. Apparently the design by Mitsi is prone to excessive heat regardless, let alone putting 100% of the torque through the hypoid gear.

well i bought it to have a laugh with, and got a bit carried away after the installation of the plate diff haha. the case seems to be flawless though. am about to go asnd have a look at the shaft. better in daylight and investigate what has accually happened.

[Kenneth]

Yeah, plate diff really does bring it alive. I couldn't get over just how easy it was to break traction though.

I did what could be done to strengthen it, so it'll be interesting to see how much abuse it handles.

[Adam.Findlay]

yeah ive had my one burnout with it now that the plate diffs in im gna see how she handles around ruapuna with my slicks on. but it made a scarily perfect shear mark on the shaft it broke. didnt get a chance to take photos tonight but will tomorow. looks like its been laser cut. id say if its completly sheared the halfshaft the transfer will take a bit of abuse

[Adam.Findlay]

43849438484384743850
well here are the results, im still amazed how the diff/gearbox/transfercase didnt fail before this and at how perfectly it sheared off

[Fully]

Thats a clean break, too much torque =)

[ILLEGAL]

good stuf! will be good to see footage of this car in action :)

[Patryn999]

Rumor was that you just poo's'd another one. Maybe the left side this time? haha

[Adam.Findlay]

yep the left side just snapped last night. definatly a weakpoint, time to go back to 4wd for a bit until i can get stronger shafts

[Louis]

this may be of interest to you, to beef up the rear shafts.
"
OK DUdessssss........ It is confirmed that EVO 10 rear S-AYC Differential fits our cars(Legnum, Galant VR-4). It fits like it was made for hehe.


OK, problems

EVO 10 uses a bigger diameter axles shaft meaning that you would need to change the HUB carrier for a evo 10 one or just make the splines diameter smaller to fit into stock CV joints, this is what I did. This was done for the passenger side axle.

The axles of a evo 10 are the same length as ours, but they are thicker."



check out posts around 116 in this thread

http://www.clubvr4.com/forum/showthread.php?54452-Legnum-tow-van-had-its-initial-pre-flight-checks-today

[Adam.Findlay]

the problem is i am using a st-r open diff casing with a evo 8 rs plate type lsd so evo x rear half shafts will be too short...

[scott.mohekey]

Get some custom made ones.. they shouldn't cost TOO much. I've heard of custom made prop shafts going for around $300, and these would be much smaller.

[Adam.Findlay]

yeah the problem is the way the cv cups are the shaft size is limited by the inner knuckle. because the cv cups on the open diffs have the spline going into the diff. to make a larger cv inner to accomidate the larger shaft you need a larger outer which means you have to get the inner splines machined onto a larger cup,. well so i was told by the cv specialists

[Nick Mann Services]

A stronger shaft with the same physical dimensions should be possible. Who would do it or how much it would cost is an unknown though.

[The Vee]

Interested in this as with the VR2 had no problems so far. But it is an open diff. Have found an LSD which may well fit (torque biasing rather than plate) but just wondering now if I may end up with the same problem albeit at the front rather than the rear!

[Adam.Findlay]

i had no problems until the lsd was installed. when it was rear wheel drive with an open diff it happily spun the wheels in 3rd gear even 4th. seems that shock loading is what killed the shafts though, a clutch stab to initiate a slide did the first one and the second one snapped when the rear regained traction after going to fast over bumpy roads (christchurch earthquake you see) am going to enquire about stronger shafts today

[elnevio]

Every time I see the title of this thread, I keep thinking "weakpoint=Adam's feet"! :D /haz



Is there any possibility of strengthening standard shafts, perhaps by heat or chemical treatment?

[scott.mohekey]

The weak point is VERY much Adam's feet. Maybe he should stick an auto in there to suck some of the power out.

[elnevio]

And to take the edge off the shock loading! :D

[scott.mohekey]

Exactly.. he would just end up killing autos though.

[Adam.Findlay]

Exactly.. he would just end up killing autos though.

CORRECT

haha whats the point of having 300+ horsepower and driving it as slow as possible. if i wanted economy i would have bought a corrolla or civic
i think by cryo treating the shafts you increase the hardness and as per my strength of materials paper in my engineering course hardeing a metal causes it to become more brittle which would be worse for the failure under shock load situation, if the shafts were failing under uniform accleration hardening would definatly be an option,
i did go and see a drive shaft specialist before work today but they said they didnt deal with cv's and that sort of stuff so reccommended me to CHP which is just up the road, unfortunatly i wont have time to see them about the matter until monday morning,
looks like im going to be driving round with spare axles in the back seat for a while longer

[wintertidenz]

Or just go easier on the poor car :P

[scott.mohekey]

or just go easier on the poor car :p

hahahahahahahha

[Mr.Salas]

Use evo 8 RS axles???? maybe?????

[scott.mohekey]

Pretty sure Adam found another weak point today.

[The Vee]

Oh no! Come on Adam.....................spill:)

[wintertidenz]

Let me guess, he blew up the rear diff? :P

Adam - be nicer on your car LOL

[Adam.Findlay]

yip rear diff decided to give way on friday night am in the process of putting the evo lsd into a new diff supplied by scott and into the car, also converted back to 4wd to stop any further breakages.. for now.

[Kenneth]

Well, I am happy enough about the strength of the transfer case now... :)

[scott.mohekey]

Kenneth, maybe you should weld up a locked rear diff for him too then.

[Kenneth]

I can't see how that would increase the reliability of the parts in question...

[scott.mohekey]

No, it would just make him more likely to break things. :D

[elnevio]

I think you need to start looking at some driveline parts from a truck! :o

Wonder if anything from the Fuso/Canter lines would bolt straight in?! :D

[ILLEGAL]

would new mounts for a nissan rear end be out of the question? or how about a starion rear end? of cause a custom job

[scott.mohekey]

I'm considering using a nissan rear end (and front actually) in my ute/v8 conversion. The rear end because it should be pretty tough, and the front end because the skyline I'll be taking it out of already has a longitudinally mounted engine which will make the steering setup a lot easier.

[Adam.Findlay]

yeah ken the transfercase is solid as a rock, im going to put it into my friends gsr when we manual convert it for a laugh until i can sort out stronger rear end,
and as i suggested to scott a nissan rear diff with custom mounts and axles could do the trick but where the back plate mounts to the subframe could be a issue and not to mention the size of the diff.
and that evo lsd is pretty much a road legal locked diff anyhow its shimmed so tightly it sometimes scuffs the tyres slighly on low speed u turns and stuff like that

[Kenneth]

You might be able to get a pinion and crown gear from a Evo 7+ which has bigger teeth.

The thing about getting a rear diff from another vehicle is that if it isn't a trans axle, the rear diff is the final drive ratio and as such it tends to be higher than the 3.3125 ratio we run.
Ideally you would want something a bit less than standard to reduce wheel torque a touch and increase top speed.

[Adam.Findlay]

well i have a evo 5 gearbox lined up for those ratios, would evo 7 ayc crown and pinion fit or will it have to be a evo rs one.

[Kenneth]

Evo 5 runs a larger final drive reduction than a VR-4 so you would just end up with even less top speed / traction. Without the ability to rev like the 4g63 you would be changing gears way too often. With the internals being essentially the same, there is no strength gain in going to an evo gearbox either.

I don't know about the AYC crown and pinion vs the LSD, the VR-4 ones look similar but someone would need to look up the part numbers to see if they are the same. If no one beats me to it, ill look it up when I am at home.

[Adam.Findlay]

yeah ill stick with the vr4 final drive in the gearbox but use the evo 5 gearset for the taller gearing.
thankyou kenneth that would be much appreciated, im still considering a r200 nissan diff conversion though depending on how hard it would be to fit. + ratio difference

[Kenneth]

Oh yeah, thats right... The AYC diff does not show internal parts :( I think mitsi only really sell it as a full assembly
I don't know whether that means they ARE the same, or if you are just stuffed if you have AYC and blow the crown and pinion. Could be worth while tearing down an AYC diff to see if the parts are the same with the non AYC.

One interesting thing is that at some point mitsubishi upgraded the gear kit as there is a second part number listed for it... It appears to have come out on the manuals exclusively (SNGF3 and LNGF3 classification), the other part number (which is shared with non-VR-4s) came out on the autos.

[Adam.Findlay]

ah so the sngf3 is the manual type v vr4 diff where the st-r has the lngf3 diff. possibly a strength difference there?

[Kenneth]

SNGF3 and LNGF3 are Galant and Legnum classifications for the same trim level respectively. Someone like Brad might have a better grasp of what all that rubbish actually means than I do :P

[elnevio]

Both facelift manual Type-V VR-4s. SNGF3 is the Galant flavour, and LNGF3 is the Legnum. :thumbsup:

[Gly]

http://www.trademe.co.nz/a.aspx?id=379580137

over it??

[Adam.Findlay]

figured if someone is willing to pay enough for it ill part with it and put $$ toward my bigger turbos if not ill keep it and it will either find its way back into the legnum or into the girlfriends gsr haha