t50 4A bell -> t50 2T gbox seal problem

[PULSE]

Hey guys, I was wondering if anyone knew the specs of the bolts that hold the gearbox to the engine (t50/smallport) as neither my engine nor my gearbox came with them so I've gotta go to a bolt shop to buy some. I've heard they have an irregular thread pitch so I can't just grab any bolts. Or if someone has a whole set they don't need I'll happily but them.

Also my other problem, I'll just copy from another forum

"Hey guys, I'm just starting off my 4AGE conversion into my TA22 and I decided to retain the original gearbox to save me from having to source/buy a proper 4A t50, and it also saves me from having to get a custom tailshaft. Anyway, I've removed the 2T bellhousing off the gearbox, cleaned everything up and now I'm up to the stage of bolting on the 4A bellhousing. Someone mentioned there was some issues with sealing before but I couldn'd find any info on it anywhere. What I've found is that it will all bolt up, but there are two bearings underneath it. One has the shaft sticking out of it that comes through the clutch guide, and then there is another bearing that just has a bolt on top of it. On the 4A bellhousing, the recess for this bearing part isn't as deep as on the 2T bellhousing. Therefore when the 4A bellhousing is on there, there is a 1 - 2 mm gap between the bell and the gearbox.

I was wondering what people have done to overcome this? I guess it could be machined out but that would be a pretty dramatic exercise if there is something easier I could do, like put on a thick gasket or something."


Cheers, Matt

[Golberg]

<div class='quotetop'>QUOTE (PULSE @ Jun 13 2008, 07:21 PM) </div>From memory the bolts were for a 17mm spanner/socket and I don't think they are anything special although the threads may have been more fine in thread pitch than a standard. I know I've got a set of them, but they'd be scattered in different jars and I couldn't be sure they were the correct ones.

In relation to the bellhousing, could one just be imaginative with a Dremel and grind it out? They are a fantastic tool, extremely useful.

[PULSE]

I probably wouldn't want to go at it with a dremel as I'd say it needs to be pretty close to perfect/even or else the bearing might scrub.

Anyway, I've taken some photos and here is my update, still need a few qs answered.

Sorry they aren't very good pics it was hard getting a good shot.

Okay this is the gearbox with the bell removed. You can see what I was talking about with the shaft and the bearing next to it.


This is a close up of this bearing. The disc that I've got leaning on there is meant to be covering the bearing, but I've removed it so you can see properly. I'm starting to think it might be ok to remove this disc, I'll explain in a sec.


This is the old 2T bellhousing, as you can see (just - dodgy pic) the recess is deep enough for the bearing.


This is the 4A bellhousing. The recess isn't as deep around the edge which is why it doesn't fit correctly.


Now I've found that if I remove that disc that sits on top of the bearing, the bellhousing fits almost perfect. Just as good as the 2T one fits anyway. So with a fresh thicker gasket it should be perfect. I'm starting to think that the edge in the 4A bellhousing has basically the same function as the disc that is needed for the 2T one. So basically I don't need to use the disc anymore. If that is the case then that makes my life very easy, the best way to confirm would be if anyone who has removed a 4A bellhousing from a 4A t50 could tell me if they have one of those discs or if they run without one.

Also, can I make myself a new gasket just out of normal gasket paper. I've got some laying around here and its thicker than the standard gasket but I'm not sure if its the correct material to use as the stock gasket seems to be made of a type of thin plastic.

Cheers, Matt

[shelldrake]

Matt,

The disc you are talking about is steel. The gearbox is cast alloy(?). The steel is a far better track for the bearings to run than the soft alloy. You may get problems if you don't use it. if I were you, I would take the 4a bell and the 2t bell to you friendly local machine shop. Let them carefully measure it up and machine the 4a one to match the 2t one. Might cost you $100(?) If you smash gearboxes down the line you can still take the bellhousing off and throw it on the cheaper, easier to find celica t-50 again...

[PULSE]

<div class='quotetop'>QUOTE (shelldrake @ Jun 14 2008, 12:53 AM) </div>Hey eddie hows it goin? I was directed to a thread by oldcorollas on toymods by a guy who has done it and he reckons the way your meant to do it is just remove the disc/shim. The thread was written two years ago or so, so I'd say he's driven on it without problems as he hasn't mentioned it when he replied to the thread recently. I'd like to know whether the 4A t50s have a disc/shim in them or if they actually run on that bit normally. If they normally do run on it then thats easy but if they don't I might just do it the right way and machine it. I'm pretty sure I can con the metal shop teacher at school to give me the keys again like I did last time when I made the spacers for my struts and I'll machine it down there.

Btw you still want that diff? It's still waiting here for you, just making sure you don't forget!

Cheers, Matt

[shelldrake]

<div class='quotetop'>QUOTE (PULSE @ Jun 14 2008, 01:03 AM) </div>Fair call. Just saying if it were me, I would try and replicate what toyota did. All you want to achieve is be able to mount up the gearbox to the motor. Have you thought about the clutch, flywheel, spigot bearing, issues you may run into.

Pm sent on toymods...

[PULSE]

<div class='quotetop'>QUOTE (shelldrake @ Jun 15 2008, 09:42 AM) </div>Yeah I was a bit worried about the clutch and flywheel, because someone mentioned that the gearbox is 20 spline, and 4A clutches are 22 spline. I know that the splines are different but then I asked around and it turns out that its only the rear output shaft spline that is different, the input shafts are the same. So I've just bought a clutch + flywheel setup for a 4A from clintoris on toymods. As for the spigot bearing, all I know is that I need one, don't really know what it is at this point, so once I go down and buy it I'll suss it all out.