| Author | Topic |
|---|
Location:
Ipswich
Registered:
May 2002
|
|
Sparkly bits in gearbox oil
|
Mon, 25 July 2005 22:31
|
 |
What would usually cause this? I'm trying to figure out why all my gearboxes are failing (I'm going onto my 7th T50 in 15 months). On one hand it could be that I'm just having bad luck and getting boxes that are on their way out (all 2nd hand boxes), on the other hand maybe something else is the problem.
The first 4 T50's I went through were Celica T50's, with an A bellhousing bolted on. All of them went the same way, they made lots of sparkly bits, made lots of noise, then 4th gear would pop out all the time, then 2nd, then reverse.
Then I got a JDM AE86 T50, this, too, made lots of sparkly bits, and then shattered 2 teeth in 2nd(?) gear, both side by side on the layshaft.
Then I got an ADM AE86 T50, and this is making lots of sparkles too, and looks like it's shattered some teeth in 3rd and 2nd gear, and is making a hell of a lot of noise in 4th and 5th.
Every one of the boxes except this last one has died while just cruising around town (not heavy load or high speed). Last one died under hard acceleration (which isn't even that quick...)
My car is a KE35, with a stock small port 4AGE, dynoed at 69hp atw. Engine was installed so that the sump is level, although I've noticed that with this angle when I remove the drain plug from the gearbox not all the oil comes out (there's a little bit left in the bottom). The last 3 boxes I've been over-filling the box in hopes that it would make it better. I'm using Castrol 80/90 oil, some sort of yellow-green stuff. Clutch is a stock item with a heavy duty pressure plate, Exedy or something like that.
Split 2 of the old boxes apart yesterday, and noticed that there's a bit of corrosion on the gears and bearings (how does this happen when the box is full of oil?), on the Celica T50 it's so bad that you can feel it when you turn the gears. There are also lots of small scratches on the wear faces (I don't know which way the engine turns, I'm guessing it's the leading face), some of them are pitted a little too.
Here are some pics:
Broken teeth
Sparkly oil
Corrosion and scratches on wear faces
More pictures
Any ideas? I find it hard to believe that 69hp atw can kill so many T50's, especially when I hear of drifters pushing a hell of a lot more power and doing clutch dumps etc everywhere and not having any problems...
|
|
|
Location:
Ipswich
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Mon, 25 July 2005 23:20
|
|
|
And yes, I do use the clutch when changing gears...
|
|
|
I Supported Toymods
Location:
Sydney
Registered:
December 2002
|
|
Re: Sparkly bits in gearbox oil
|
Mon, 25 July 2005 23:52
|
|
I assume you mean you get 69kW at the wheels not hp.
I hate to say this but T50's aren't all their cracked up to be.
Witzl and I would have gone through a lot more T50's if we could have got traction... as it was we went through more T series diff's than we did oil filters!
|
|
|
Location:
Rosanna, Melb
Registered:
June 2002
|
|
Re: Sparkly bits in gearbox oil
|
Mon, 25 July 2005 23:54
|
|
Something is really wrong. I have belted second hand T50s with 140rwhp and only broken one in two years (that was autocrossing too).
The sparkly bits are metal filings being ground off your gear teeth/out of the bearings. Not a good sign.
If this is happening with every box then check the bits you haven't changed each time you swap boxes. Does your bellhousing mate to the block properly? All bellhousing bolts and gearbox stays bolted up tight? Tailshaft doesn't bottom out on the output splines?
Not sure if any of this will help, but good luck finding the culprit.
Hen
|
|
|
Location:
Brisbane
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 00:07
|
|
Sparkly bits in the oil isn't unusual in any gearbox that has several hundred thousand km's unders its belt. This in itself doesn't mean much.
As to why you break gearboxes, it's all about driving style. Obviously you didn't build that car to drive sedately to the shops. Give it a bit of stick and the weakest link manifests itself - and in this case the T50 is a pretty weak link.
What clutch are you using? An agressive clutch can significantly shorten the life of any gearbox. I've killed 3 Supra 5-speeds and IMO a large part of the blame rests with the 5-puck ceramic clutch I'm using. Shock loading is what usually kills gearboxes.
|
|
|
Location:
Ipswich
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 00:08
|
|
Actually, 69hp.
Bellhousing looks like it mates with the block properly, how can I be sure? The bellhousing bolts stay tight, and all except the top 2 are torqued up to spec. I can't reach the top 2 bolts with the torque wrench so I just tighten it as tight as it will go.
Taishaft doesn't bottom out, and has been replaced twice (going from Celica T50 to AE86 T50, and then changing diff from standard KE35 to RA23)
Can anyone confirm with me what the angle of the box is supposed to be sitting at? Was I told correctly that if the sump is level, then everything else (gearbox included) would be at the correct level?
That said, it doesn't look like the box was running dry up front, because even the rearward gears show signs of scratching and stuff... How much scratching is "normal"? How else can you tell if the gears are stuffed?
Also, can I swap the Celica T50 layshaft into an AE86 housing (and use the AE86 main gears)? They *look* the same, except maybe the end bearings look a little different. And the AE86 ones have a channel cut through some of the gears and textured edges, I would assume to help carry the oil around... Or are gearbox gears like diff gears, and have to be replaced all together?
|
|
|
Location:
Ipswich
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 00:12
|
|
Norbie: Yes, am aware of that too. However, have never had any issues with gearboxes in any other cars (although none of my other cars have had this much power except my GSR), and I do use the clutch when changing gears. That said, that could be it, maybe T50's just weren't designed for motorsport? But the abuse that some people I know throw their T50's through (and survive) makes me scratch my head...
My clutch is just a standard clutch, with a heavy duty pressure plate. That's what I was told when I got it anyway... It's blue, and it says "exedy" on it...
|
|
|
Location:
Ipswich
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 00:14
|
|
Should I be using a different oil maybe? Hmm...
So basically at the moment it's just sounding like the T50 isn't really up to scratch, and I should look into something bigger (W50, W55 etc?) Seems like overkill for an engine that isn't even pushing much power at all...
|
|
|
Location:
Brisbane
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 00:27
|
|
Overkill? Perhaps - but if you've killed 7 T50's, I think the writing is on the wall. Bigger gearbox for you. 
|
|
|
Location:
Sydney
Registered:
October 2003
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 00:29
|
|
My vote is for mechanical sympathy. Some people get a long time out of clutches, gearboxes and diffs, some people don't.
ie, my clutch was knackered when I bought my car, but I still got 50,000kms out of it before I pulled the whole engine out. There's no way in hell I'd ever mush a gearbox.
You say you use the clutch every gearchange, but there's a lot more to using the clutch than just pushing it in and letting it out. Not saying that you are letting it out too quick etc, but something you should adjust if you are. Without trying to sound too much like a tosser, you'll know how hard you can be by how it feels, if it feels a bit tough on the car, then you're probably doing some damage.
|
|
|
Location:
Ipswich
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 00:41
|
|
Oddly enough, when I was running the first 4 T50's, I was still using the stock Corolla diff (which is *tiny*)
Anyways, I suppose I should start saving pennies to change to a W5x box and bring out the sledgehammer and start making my transmission tunnel bigger 
|
|
|
Location:
Rosanna, Melb
Registered:
June 2002
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 01:14
|
|
I seriously doubt that this is just a T50 being too weak problem. As I said above I ran T50s behind a reasonably serious ZE for two years and only ever broke one (it snapped teeth off second on a rough autocross track). I had a heavy duty full face organic clutch and you could pull second gear burnouts off the line, which I did regularly at drift nights. I was not kind on the gearbox at all and it still stood up to drift nights every month and a few quarter mile trips and regular daily driving.
I think there must be something strange or misaligned about your setup. A T50 should cope. I know plenty of people putting similar or more power through a T50 without chewing through 7 of them. What the problem is I can't really help with, but I don't think that it is just that the box is too fragile.
However you may decide that fitting a W box is an easier propostition than diagnosing the mystery ailment.
Hen
PS, you do have a spigot bearing in your crank don't you?
|
|
|
Location:
Ipswich
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 01:18
|
|
Yes, have spigot bearing.
How do I check if anything is misaligned? It all *looks* okay to me, would taking lots of photos of my car and posting them up here help? Or is it a case of bringing my car to a... where would I take it? A gearbox shop? A normal workshop?
|
|
|
Location:
Canberra
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 06:53
|
|
Your gearbox oil is WAY too thick. Early Toyota boxes use 70-75 hypoid gear oil.
Toyota use faily tight tolerences when building gearboxes. Imagine what is happening between the gears.............when the oil is too thick.
Way back when I were a lad,  90 was the only GB oil around. We mixed 1/2 a litre of Dextron ATF with the 90 grade oil. Some guys even used straight ATF.
As Norbie said, "some sparkly bits will always be present in your GB oil"
A lot of the T50's have been sitting around for years, atmospheric changes will draw mioisture into a GB, that will account for the corrosion.
cheers Chuck.
|
|
|
Location:
Ipswich
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 06:55
|
|
|
So I should actually use thinner oil? Hmm... I've always been told to use 80/90, but I'll go look for some thinner stuff if you recon it'll get the box to last longer...
|
|
|
Location:
brisvegas
Registered:
August 2004
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 23:10
|
|
jsut a quick question..did you put a spigot bearing in the end of the crank when you got that motor in?? you said it was a small port..ie FWD..FWD don't use spigot bush/bearings..i have an 4 puck carbon NPC clutch (looks like your is an NPC too) and i have only gone through one box..many diffs and axles though..and mine literally make double the hp and torque as yours..and i drift/drag the arse off mine.. 
Matty
|
|
|
Location:
brisvegas
Registered:
August 2004
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 23:11
|
|
also if its a bit notchy..just whack some auto fluid in there..maybe try a 50/50 mix of your normal stuff and auto fluid..
Matty
|
|
|
I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Tue, 26 July 2005 23:23
|
|
Check to see what the sparkly bits are first.
Use a magnet to see if they are attracted....will suggest that it is something made from iron. If there is no attraction, then likely to be non ferrous - ie synchromesh bits.
|
|
|
Location:
Ipswich
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Wed, 27 July 2005 01:09
|
|
gianttomato: Will check with magnet tonight. Someone else had a look at my gears yesterday (from one of the old boxes) and said it looks like some of the layshaft gears are getting a hell of a lot of load on them, they're really really worn.
Gearshift has always been very notchy (in all my boxes, especially the two AE86 ones). Have tried running auto fluid in one of the Celica box and it did make shifting easier, but I wonder if that would be too thin and make the box die early? Have also tried that "uber goo thick stuff" that's meant for like... umm... helping with older engines and gearboxes and stuff, and it made shifting very very hard while it was still cold.
drift86levin: I got my engine from Anthony Kellam, was told that the spigot bearing had been put in. Doesn't it not work if you don't have one of these? I think I remember seeing a bearing-like thing in there when I last took the box out...
|
|
|
Location:
Brisbane
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Wed, 27 July 2005 01:34
|
|
|
No spigot bearing = unsupported input shaft = premature failure.
|
|
|
Location:
Ipswich
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Wed, 27 July 2005 05:34
|
|
|
Spigot bearing goes into the hole in the middle of the clutch yes? Like, where the input shaft goes. What does it look like? Just a standard sort of bearing? I'll have a look tonight when I get the old box out.
|
|
|
Location:
Canberra
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Wed, 27 July 2005 06:09
|
|
Spigot bearing is fitted to the centre of your crankshaft. The reduced diameter section of the GB input shaft rides in the spigot bearing. The spigot bearing, may be visible through the splined centre of your clutch plate, if you can get your head into the gearbox tunnel.
cheers Chuck.
|
|
|
Location:
Brisbane
Registered:
February 2003
|
|
Re: Sparkly bits in gearbox oil
|
Wed, 27 July 2005 06:19
|
|
| demuire wrote on Wed, 27 July 2005 11:09 |
Have tried running auto fluid in one of the Celica box and it did make shifting easier, but I wonder if that would be too thin and make the box die early? Have also tried that "uber goo thick stuff" that's meant for like... umm... helping with older engines and gearboxes and stuff, and it made shifting very very hard while it was still cold.
|
some bog-warmer gearboxes used auto-trans fluid (a few 5speed sigma boxes did this) - but not sure if any toy boxes ahve done this?
is there any other drive-line issues, e.g.:
-correct pinion angle on diff
-premature wear/failure of uni joints
-isolator in rear gearbox mount failing?
-rear box seal failing
-output shaft bearing
-excessive oil loss from gearbox
cheers,
charles.
|
|
|
Location:
Ipswich
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Wed, 27 July 2005 06:36
|
|
|
Pinion angle on diff is correct, as far as I know. Uni joins are ok. What is an isolator? Rubbers on the gearbox mount look okay. Rear seal on current box has a slight leak, but no noticeable oil loss. Output shaft bearing, I don't know, but it doesn't make any unusual sounds.
|
|
|
Location:
Brisbane
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Wed, 27 July 2005 07:06
|
|
| thechuckster wrote on Wed, 27 July 2005 16:19 |
[
some bog-warmer gearboxes used auto-trans fluid (a few 5speed sigma boxes did this) - but not sure if any toy boxes ahve done this?
|
V160 and V161 run autotrans according to ze norbs.
Yeah check to see if you have a spigot!
Cheers
Wilbo
|
|
|
Location:
Brisbane
Registered:
February 2003
|
|
Re: Sparkly bits in gearbox oil
|
Wed, 27 July 2005 08:57
|
|
| demuire wrote on Wed, 27 July 2005 16:36 |
What is an isolator? Rubbers on the gearbox mount look okay.
|
question answered
if there was no spigot bearing then you'd expect ot see early failure of the input shaft bearing? is the damage to the layshaft up towards the front? or all over?
only thing that i can think of is that when you bolt up the bellhousing you do something that affects end-play/thrust on the layshaft - somehow making it more vunerable to damage?
did you tweak with shifters/selectors when installing into the car? you saying that you used auto-trans fluid to make shifting easy?
cheers,
Charles.
|
|
|
Location:
Ipswich
Registered:
May 2002
|
|
Re: Sparkly bits in gearbox oil
|
Wed, 27 July 2005 14:49
|
|
Yes, have spigot bearing (or at least, a bearing in the crank that looks about the same size as the input shaft end)
Damage to layshaft is all over. Umm... I've bolted on the bellhousings for all the gearboxes except the one I just put into the car, maybe you're on to something there? Is there a "wrong" way to bolt up a bellhousing?
And no, no tweaking with the box. With the auto trans fluid someone suggested it to me, so I tried it. It did make shifting easier, but I felt uncomfortable about it so I changed it back to normal fluid.
Looked at yellow toyota manual, it says for T50 use SAE90.
|
|
|
