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FNFAST VR4
29-07-2007, 01:33 AM
Hey all,

Well, my beloved gearbox is coming out again. Seems the mark I put down to being a casting mark was actually a crack so my gearbox started leaking again....

Sooo, what I need to know is, do you guys recommend anywhere (South of the CBD preferably) to get it welded up? I will remove it and strip it down (I assume this is necessary) and just take it in somewhere.

I've been told Machine Part Welding in Penrose are ok, but charge an arm and a leg.

As usual, any advice greatly received!

Gly
29-07-2007, 05:20 AM
any welding/engineering place can do it...

i might be able to get it done thru my dad.... depends where and how big the crack is?...

is the casing cast aluminium?

FNFAST VR4
30-07-2007, 08:24 PM
any welding/engineering place can do it...

i might be able to get it done thru my dad.... depends where and how big the crack is?...

is the casing cast aluminium?

I'm not too sure. Don't really know my metals all that well. I might start the removal process this Saturday...

FNFAST VR4
16-08-2007, 10:22 AM
Well, as per Dicky Tims instructions, the gearbox came a hell of a lot easier the second time. 6 hours all up as opposed to about 3 weekends of farting around...

Got it apart, and gave it to a mate of a mate who welds things for helicopters apparently? He took it last night, and while just sitting there said there at least two cracks in it... He is going to clean it up and give it a thorough inspection.

I've heard that the alloy they are made out of is difficult to weld, I have little welding experience so don't really know...

Is it going to be as good as new once its welded (assuming its done right) or will it potentially be weaker or what?

On the plus side my input shaft seal is working perfectly! No oil whatsoever in with my pretty pink clutch :happy:

Gly
16-08-2007, 10:29 AM
cast alloys tend to have a brittle nature, and will crack when stressed rather than bend,

when welded (heated) it changes the structure of the metal and makes it soft.
which will now give it the abbillity to bend.

if he is a good welder, and it gets a good weld, it will be as good as new.
but this depends on the condition of the metal as well.

if its only a couple of small cracks i dont see any problems with it.

but if its full of cracks (all over) theres a good chance that the whole casing is brittle/full of porusity in which case its a write off.

FNFAST VR4
16-08-2007, 10:51 AM
cast alloys tend to have a brittle nature, and will crack when stressed rather than bend,

when welded (heated) it changes the structure of the metal and makes it soft.
which will now give it the abbillity to bend.

if he is a good welder, and it gets a good weld, it will be as good as new.
but this depends on the condition of the metal as well.

if its only a couple of small cracks i dont see any problems with it.

but if its full of cracks (all over) theres a good chance that the whole casing is brittle/full of porusity in which case its a write off.
AH CRAP! here's a pic of where the main one is. The other one is in that little window shaped stamping/imprint thing on the other side. I didn't take a pic of that. Only realised it was a crack after I saw it from the inside.

I'm guessing it's somewhat difficult to find a replacement manual gearbox?
uploaded/2931/1187257672.jpg

Gly
16-08-2007, 11:03 AM
**** me thats a big crack! at least its in a relatively straight line.... and not branching out....

if hes a good welder and with a bit of luck it looks fixible

strange that it has cracked thou?
had it got any noticible marks from being dropped?
or any internal damage indicating a gear set blowing up inside it?

would have to have been subjected to some stress to get it to do that.
may have some casting imprefections in the metal from factory?

FNFAST VR4
16-08-2007, 11:36 AM
**** me thats a big crack!

I bet you say that to all the boys!!!

It was driving fine right up til the day the input shaft bearing died. All I can think of is the broken input shaft bearing put stress on it and made it crack. I don't recall it leaking at all until that bearing went.

The input shaft seal had been on its way out for a couple of years, it would leak a bit, the clutch would slip for a bit then it would get over it and keep going for another month or two.

I don't know what caused the bearing to give up, as it never got noisy (until it died then it sounded like ball bearings rolling around in my sump) or anything first. When I took it all out I didn't figure that line to be a crack. I assumed it was just crap from when it was cast or something as it is so long and seems to run in a semi-straight line. But no, once it was all back together it was still leaking. I patched it with knead-it til I had the coin to pull it apart again :embarasse

mpau009
16-08-2007, 07:44 PM
I dont know how it works with gearboxes, but i have dealt with a couple of alloy boat trailers at work, and once the frame cracks, we generally advise to throw them out. This is because even though you can weld them up, and the repair will be stronger than the metal that was there before, it usually meant that the rest of the frame was fatigued, and it would just crack somewhere else within a short period.

From looking at that, i would say that it should be easily repairable. But it might be worth getting it checked professionally. I'm not sure how they do it, but i think there is a process for finding out just how tired it is.

If you cant find a welder, give me a PM too, we should be able to point you to a few who specialise in welding/repairing alloy boat hulls and the like.

FNFAST VR4
16-08-2007, 08:31 PM
Sweet, will do. I'm waiting on word from this guy, I'm assuming if he can weld things for helicopters he must be able to weld ok ha ha.

It's been a week.... I miss my car already :(

FNFAST VR4
05-09-2007, 01:30 AM
**** me thats a big crack! at least its in a relatively straight line.... and not branching out....

if hes a good welder and with a bit of luck it looks fixible

strange that it has cracked thou?
had it got any noticible marks from being dropped?
or any internal damage indicating a gear set blowing up inside it?

would have to have been subjected to some stress to get it to do that.
may have some casting imprefections in the metal from factory?

Heard from the welder today, he definitely can't do it himself as his welder isn't powerful enough to deal with the thicker parts of the casing. He is going to see if a friend of his bosses can do it, but he doesn't know what the cost is likely to be. Does anyone know what price range I would be looking at for this type of job? I have an uneasy feeling about the whole thing all of a sudden...

KHK
05-09-2007, 04:54 AM
welding costs u some money and with uncertainty on its lifespan afterwards
isn't it better to find a replacement as a long term solution? though it may cost u more

Kenneth
05-09-2007, 05:28 AM
The following advice is given without any warranty...

If it were me I would take it to an engineering shop that has the equipment. Say a marine engineering outfit. Ask them to do a cash job for you and perhaps offer a box of beers.

In the mean time you can save some time by doing the prep work yourself. You will want to cut/grind into the crack to take out the material in a V shape. you don't need to take out too much, just make sure you get some depth in there so the welder can get some material into it. I am not sure how far you would want to go into the casing, but I would expect you would want to go at least 50% down. (You might want to verify this, as it could be that you should take out all the way to the other side, removing the cracked aluminum completely. though this would create more work for the welder, it will ultimately be better. Still wants to be a V shaped groove though)

If you were to do this along the length of the crack (probably a bit beyond to make sure) and then clean up well with some form of oil/grease remover a welder should be able to (if they have the time) fix it up in front of you.

Of course you should ring up said welder first and find out if this is the correct thing to do (though I believe it is)

From what I understand you need to cut the material away to ensure they can add enough material to ensure its strength and so the crack wont grow again. If someone thinks to just weld over the top of the crack, I would be a bit dubious about the quality of the job.

FNFAST VR4
05-09-2007, 07:45 AM
welding costs u some money and with uncertainty on its lifespan afterwards
isn't it better to find a replacement as a long term solution? though it may cost u more

Originally I did try to get a second hand gearbox, but the places I tried all said they couldn't get them.

I don't remember who exactly I asked other than Kempy's. Any other suggestions?

FNFAST VR4
05-09-2007, 07:49 AM
The following advice is given without any warranty...

If it were me I would take it to an engineering shop that has the equipment. Say a marine engineering outfit. Ask them to do a cash job for you and perhaps offer a box of beers.

In the mean time you can save some time by doing the prep work yourself. You will want to cut/grind into the crack to take out the material in a V shape. you don't need to take out too much, just make sure you get some depth in there so the welder can get some material into it. I am not sure how far you would want to go into the casing, but I would expect you would want to go at least 50% down. (You might want to verify this, as it could be that you should take out all the way to the other side, removing the cracked aluminum completely. though this would create more work for the welder, it will ultimately be better. Still wants to be a V shaped groove though)

If you were to do this along the length of the crack (probably a bit beyond to make sure) and then clean up well with some form of oil/grease remover a welder should be able to (if they have the time) fix it up in front of you.

Of course you should ring up said welder first and find out if this is the correct thing to do (though I believe it is)

From what I understand you need to cut the material away to ensure they can add enough material to ensure its strength and so the crack wont grow again. If someone thinks to just weld over the top of the crack, I would be a bit dubious about the quality of the job.

Suppose I will wait and see what the guy comes back with... I don't have the equipment to go starting it myself. Will see what happens I guess. I think I am just a bit gutted that its taken him this long to come back to me and say he can't do it, where I would have thought that would be apparent rather quickly to someone who works with metal all day every day. Having to squeeze my 6 foot 6 frame into a honda prelude every day isn't helping my view of this whole exercise!

KHK
05-09-2007, 01:26 PM
Originally I did try to get a second hand gearbox, but the places I tried all said they couldn't get them.

I don't remember who exactly I asked other than Kempy's. Any other suggestions?

i emailed Kempy sometime ago requesting for a manual vr4 gear box, they even didn't reply
i guess basically u have not many choices, try find a good welder and get a good price

FNFAST VR4
06-09-2007, 01:55 AM
i emailed Kempy sometime ago requesting for a manual vr4 gear box, they even didn't reply
i guess basically u have not many choices, try find a good welder and get a good price

Yeah, the reply I got from them was I think 3 words... No, and the persons name ha ha ha

Gly
06-09-2007, 06:08 AM
bring it to me and ill get a second honest opinion.

FNFAST VR4
06-09-2007, 10:13 AM
bring it to me and ill get a second honest opinion.

I'll try and get it off him. Thanks for that though man.

Just found a second hand one on trade me for $700...

FNFAST VR4
23-09-2007, 11:02 AM
bring it to me and ill get a second honest opinion.

Right got it back (unwelded...) Would you still be able to get it looked at for me?

Apparently it could need to be x-rayed? From what the guy told me, if I get it welded, and then stick it in a bake oven for an hour, then let it slow cool it will be as good as if it was new.

It's all beyond me! Been years since my automotive course, and the metal unit was only one part of it.

Gly
23-09-2007, 12:05 PM
well i could get it welded,
but not tempered, in an oven...


send me a pm and we can organise something