RA28 Help

[rancidpunk]

Thats what I was starting to think timbo, I've gone off the idea of that deal. Started to search for a G-series diff as some are only 10mm(?) wider than the original T series and I want ot be able to fit the wheels I bought under the car! The modification of the mounts isn't really that much of a concern to me, seems like a pretty simple job for an expirienced fabricator/welder, it's more the mods to the flange, anyone care to explain to me how that works?

[TheToyman75]

Rancid,

The mods to the flange people are most likely refering to is the Diff Flange where the tailshaft bolts up to. You will need to have the tailshaft modified with the right flange to suit your choice of diff. This is not an issue tho as when you fit a bigger diff you generally need to change the length of the tailshaft anyway.



If you look at this poor quality pic the diff flange is visable and you can see 2 of the bolts that hold the tailshaft to it. As you can see its allot bigger than a stock RA28 one. (That pic is a Hilux diff in an RA28 )

[rancidpunk]

Thanks toyman, so if/when I do the hilux diff conversion I'll need to get a new tailshaftt aswell? Will it need to be modified at the other end to fit the stock celica gearbox? My other question is when I finally do the 1GGTE conversion W/ a w58 GB will I need to get the tailshaft modified again?

[Scoobzd]

you can either get a new tailshaft made up ( very $$$$$ ive heard ) or you just keep your stock one and get it modified, i.e different g/b yoke and different flange put onto diff facing side.

It can be cheap, but you want to make sure that it is balanced right, otherwise you will go through uni joints every couple of months.

[rancidpunk]

Thanks for the pic toyman, is that a custom made tailshaft?If not what is it, did you get it modified, i.e. getting rid of the uni-joint to make it a bolt on? Who is good in Melbourne for stuff like this?

[TheToyman75]

Rancid,

That tailshaft on mine is a full custom 1 piece shaft. Unfortuantly I don't know anywhere in melbourne I could recommend for you. In Sydney I recomend Sydney Driveline Services.

[SilverRA23]

Hardy Spicer in Dandenong do good work for tailshafts etc, but they aren't cheap.

[o_man_ra23]

Hardy Spicer up here are cheap as... couple of hundred for a full custom single piece tailshaft (you supply the yoke and flange, tilt tray the car there, and they will make it to suit), really is a good price in the end.

Brett_Celicacoupe put a 1G-GTE (Gen3) into his RA40 (same diff except width), bumped the boost up to 16psi, and proceeded to flog the living shit out of it. Took 8 months of continual power fishies, burnouts, hard launches and drag runs to kill the diff, then it was only the centre which spat some spider gear teeth. Axles were still holding together. If you drive somewhat sensibly, and don't give the diff too much curry, it will hold together surprisingly well (if you weld the centre up, you will snap axles every second week). If you have a good mate who is a fabricator, then get an F series diff and shorten it. Same flange, standard tailshaft fits, available in the same 4 stud, available with disk brakes (or you can use the RT142 avante disks), available LSD, and more than strong enough to take a 1G. Plus it's much much lighter than a G series.

Brakes - don't discount the option of doing the $250 brake upgrade (search that in the tech section). Involves vented RA60 disks, XT130/RT132/RT133 Corona struts and hubs, and MX63 Cressida callipers. Very little bracketing/mods to be done, parts are easily available, and although the callipers are single piston, they have massive pistons and are quite surprising. Also, RA28 front springs are the same as the aformentioned Corona variants (I should know, I am running RA28 King lowered springs on RT133 struts... King catalogue even lists them as the same part number). This setup will still fit under 14's, but in your case this is not an issue. Standard RT132 brakes (with the twin piston sumitomo callipers) are indeed an improvement over standard (this is what I am running, with bendix advance pads and surfaced disks), but they will be too lacklustre for the 1G.

Front swaybars from MX62 Cressidas also fit, and they are 24mm thick. Rear swaybars are available from Whiteline which bolt to your lower trailing arms and are adjustable to be able to balance them to your front swaybar.

River is right, make sure your car is rust free first. Cut and weld ALL rust, as rust is contageous and spreads. So a little bit of panel rust that you bog up thinking because it isn't structural could lead to disaster later. And don't leave the car in primer out in the weather, primer is porous and will lead to rust. Any method you can use to prevent further rust from appearing is worth the effort (deodourised fish oil is your friend).

Once your suspension, brakes and driveline are sorted, then as mentioned, start looking for a suitable halfcut. Occasionally 1G mid sumps (with pickup) turn up for sale, if you can find one it will save you modifying your sump.

I think that's enough info for you to start with. Good luck with the project, please make a member's ride thread and keep us all informed with your progress. Also may I direct you to the Classic Celica Dedicated Thread found in the General Car Talk section, it is a wealth of knowledge for these old girls.

[timbosaurus]

Good info the diff Owen.

Just want to correct that even Mid sump 1G's need to be modified to clear the idler arm.

[o_man_ra23]

Thanks for the correction on the sump Timbo... but it is a SHITLOAD less mucking around than trying to correct a front sump.

[RAd28]

Correct me if i'm wrong, but i was under the impression that the only way to make a Front sump 1G fit, was to remove it and install a mid/rear sump? AFAIK mid sumps require quite a bit of effort relative to a rear sump which requires some elbow grease and some loving from a wooden handled yanky spanner

[timbosaurus]

I'm not speaking from experience, but i'd assume the front sump is needed when using the TA23 Xmember. Maybe then it'll fit without modification?

[o_man_ra23]

Correct me if i'm wrong, but i was under the impression that the only way to make a Front sump 1G fit, was to remove it and install a mid/rear sump? AFAIK mid sumps require quite a bit of effort relative to a rear sump which requires some elbow grease and some loving from a wooden handled yanky spanner

Can't speak from experience, only what I can try to recall... and an 18R-C having a mid sump from factory (when installed in an RA28) leads me to the notion that a mid sump is going to be the closest fit... Anyone got photos of the 3 different sumps??

[TheToyman75]

The 1G front sump requires no modification when used with a TA23 Xmember - But you will need to use a T-18 front sway bar

[o_man_ra23]

And find a TA23 xmember... bit harder than it might seem straight up (but they do crop up from time to time, so don't abandon all hope on that). T18 swaybar is easier to find... can you get aftermarket T18 swaybars to try and help balance things up??