6 speed LSD Mk1 gearbox build

[PW@Woodsport]

Yep a bent bracket will certainly do it.

I've also found the gate return spring at the stick end goes weak after 30 years, if you take that out and bend it a little you can make it return to the 3rd/4th gate better.

[kaiowas]

I had the whole shifter apart, removed the 25 year old grease which had gone like treacle and regreased it. The bent bracket meant that the gearbox and the shifter were trying to centralise to slightly different positions and the spring at the shiter end was winning which was putting the gearbox end between gates. Both sets of springs are working together now.

[PW@Woodsport]

Good stuff, i've noticed these 6 speeds becoming more popular now as tired 5 speeds become more troublesome, i'm doing about 2 per month at present.

[stragenmitsuko]

I took my celica C60 apart today .

Previous owner did mention it was a bit scratchy
between 2nd and 3d gear . I took a chance and bought it anyway .
Hoping it would be a synchro or a bearing .

Turns out quite differently ....
There's a piece of the 1/2nd selector fork that broke off .
It got caught between the teeth of the 2nd gear , causing
half a tooth to break off on the input shaft .
Making the entire gearbox worthless I guess . .

The selector fork can be salvaged from the five speed .
It's exactly thesame .
The input shaft is a problem .

Paul you woulnd't happen to have a spare input shaft
maybe form a C60 that's beyond salvation ?

Pat

Btw the gearbox came apart quite easily , but the force needed to pull the
six'th and fith gears is quite impressive .
Had to machine a couple of dedicated pullers to get the job done .

[PW@Woodsport]

I will have a look today and let you know

[stragenmitsuko]

Setting the diff preload today .
I don't have a torque meter , but it can also be done
wth a 0- 2.5 N dynamometer .

I'm using the stock MK1b diff .
Maybe it's worth mentioning that , unless i'm mistaking , the mk1B bearings have to be used , not the c60 's . This is because the mk1b open diff has other dimensions compared to the c60's open diff .
Can't tell for the lsd , cause I don't have one .
Luckily the outer races for both bearing systems are thesame diameter .

I've also made ( lathe , mill ) the SST for torque-ing the diff .
For an open differential , the procedure is slightly different .
The sst is no more then a shaft with a slot milled at the end and a hex on the other . Easy to make , even without a mill

I was gonna upoad some pictures , but apparantly I can't post url's or pictures . Anyway , if someone needs them I'de be happy to share , just neede to find a way how .

Pat

Paul , any luck on the input shaft ?
I don't know , the donor gearboxes for the lsd's , do they also have that same input shaft ?

[PW@Woodsport]

Sorry for not getting back to you sooner, i'm sure you can appreciate i'm a busy guy.

I have a 6 speed input shaft here for you, cover the postage and it's yours, i would appreciate a few packets of hobnobs in return

PS. Chocolate ones.

[stragenmitsuko]

Great Paul , thx a lot .

I'll send you a pm with my personal data etc .

Pat

[stragenmitsuko]

Having finished my six speed conversion , here are some random thouhgts / remarks that might be usefull for other builders .

Working on gearboxes is fun . Really it is .
Fine mechanics , tight fittings .... I love it .

When building a six speed variuos special tools
will be needed .
No point in trying this with just a pair of pliers .
I have a lathe and a mill , so I just machined them as I got along .
A decent set of bearing splitters and pullers will also do the
job I guess . Still , for pressing certain gears and oil seals in , sst will be needed .


If you want to use the MR2 Mk1b open differntial ,
you'll also have to use the differential bearings for
a Mk1b gearbox . The six speed or the lsd diff bearings will
not fit the Mk1b differential .
Left and right side are not thesame , not for the C60 , and not for the C52 . .

Output shaft bearing has to be C60 .
C52 output shaft bearing doesn't fit the C60 output shaft .
Input shaft bearing appears to be thesame .

Mr T sells a kit of seals for a C52 . 30£ -ish .
If you decide to stick with the C52 open diff , like I did , get one .
You'll need almost all of it's contents .
Input shaft seal is pressed in 1mm , and it goes in from the clutch side .
Engine side diff seal , C52 bellhousing ,is pressed in 2.5 mm .
Gearbox side diff seal , C60 middle case , is pressed in 12.5mm .
I've machined 3 sst to press them in at these depth's .
These are measurements I took so use at your own risk .

A C52 transmission from fi a corolla or celica can also be used .
I couldnt get one from an mr2Mk1b The corolla C52 bell housing is thesame and so is the diff . But the shift lever has to be mr2mk1 , luckily for me , a Mk1a lever will also fit .

Toyota service manual says to use SSt and a hammer to install the 5fth and 6th driven gears . DON'T .Using a hammer will most likely destroy the bearings or even the gearbox case .
The output shaft is threaded m10*1.25
Use a sleeve , a washer , a nut and a threaded rod to install these gears .
That's the way the service manual for the C52 says to do it , and I see no reason why a C60 should be different .
My personal opinion offcourse .

If you want to use a hammer on the 5/6th hub on the input shaft , you can , but do support the input shaft with a wooden block . I strongly advice a press to do the job if you have acces to one . Again , no force should be allowed on the bearings .

That's about it .

Big word of thanks to Paul for sharing all his information .
Without it , this conversion would not have happend .

Oh and Paul , do correct me if I wrote something you don't agree with .
After all , I did only one gearbox ....

Pat

[PW@Woodsport]

No that's all very accurate, i would only add it is vital the diff preload is checked and adjusted, which is a whole proceedure in itself, but very important.

[fred]

hi guys im new

[stragenmitsuko]

Paul , any recomendation on what oil to use ?
And howmuch oil the gearbox should have .

I know , with the car level , I'm to fill it till overflow .
But it's somuch easier to pour in the oil with the gerbox on the bench

Pat
Currently doing bodywork , rebuilding the rear arches

[PW@Woodsport]

I use EP 80/90 but others like different oils, one guy i know runs auto transmission fluid in his.

I don't know the actual fill quantity as i have a proper gear oil syphon pump at the garage whish just fills them up until it meets the overflow. Google says 2.3L.

[IanParkhouse]

Eventually sorted myself out a new 6 speed shift pattern

[stragenmitsuko]

omg that looks awesome

didn't make a spare one by any chance

Pat

[IanParkhouse]

Had to order 9 so they're available but I don't know if I can advertise them here. You can find them if you know where to look.

[Lauren]

You'll need to pay the premium membership fee, Ian if you want to sell them here. One thing to consider though, how many members have a six speed gearabox in their MK1. I can only think of Phil.

[IanParkhouse]

Thought as much Lauren. Just really wanted people to tell me how good it looked

[Mk1Chris]

Looks good

I have a 6 speed too

[IanParkhouse]

Cheers Chris

Got to love the 6 speed, I'd rather have a 4-age with a 6 speed than my 2zz with a 5 speed