Diffs/LSD Speedo's

[sic86]

The ADM models come out without LSD. Just wondering if after you put a different diff or lsd in does your speedo still read the right speed? Or do you have to get in adjusted? How can you adjust them?

Cheers

[crazy86]

First thing, aftermarket LDS will not fit in an ADM housing, you need a completely new rear end.

Now, back to your question

No, changing centres (eg changing to LSD) will not affect your speedo. Changing your diff gears will. For example, the ADM S type diff comes with a 3.9:1 ratio, and I changed my ratio to 4.3:1. This is a change of 10%, meaning my speedo is 10% out (eg 50k speed limit = 55k on speedo, 110k speed limit = 121k on speedo.

If you want to get it adjusted, take it to an auto instruments guy, and they will most likely install a "reduction" box on the gearbox output, or re-calibrate the speedo (or both)

[Wally]

im looking for a 4.1 diff from a ra40 when i can get one!!... need a t-series though...

thanks for that craig, i was wondering it also

[Medwin_3sGTE_AE86]

Auto instrument guy...? where can i find one...? i'm running 4.8 and my speedo is waaaaay out....

[Wally]

eeek speedo way out + speedcameras = bad!!

[StockAE86]

Originally posted by WaLLY@Nov 9 2005, 07:17 PM
im looking for a 4.1 diff from a ra40 when i can get one!!... need a t-series though...
Ive got a 4.1 in my car, speedo reads 110 when im doing 104 so its not too far out.
You can also get 4.1 out of TA22, thats what mines out of.

[crazy86]

I know of one (Manly Auto Instrument Repairs) in Brookvale. He is also a VDO agent.

Other than that, try the phone book, or ask at an auto electrician, they should know.


Your running 4.8???? your car must absolutely howl like a banshee on the freeway http://www.ae86drivingclub.com.au/forums/emoticons/ohmy.gif . I guess thats one way to stop yourself speeding http://www.ae86drivingclub.com.au/dcimages/7/5/4/536981.jpg

[RobertoX]

Guys,
Just on the subject of t series ratios...

Does anyone know the types of ratios found in what cars?

I've done a search and have come across all sorts of info, some of which is:

RA40 Auto = 4.1:1

RA40 Manual = 3.9:1

TA22 = 4.1:1 & 3.9:1 (but which models??)

TE72 = 3.7:1 & 3.9:1


A database of this would be cool http://www.ae86drivingclub.com.au/forums/emoticons/wink.gif


Also are the diff centres (including carrier and everything) compatible between models? Say for instance if I got a centre with a 4.1 gear from an RA40 will the whole assembly (carrier, diff, gears brgs etc) fit my t18 axle? Without problems with the tailshaft being too short /long and these types of problems?

Cheers,

Rob

[StockAE86]

I know TA22 and RA40 the whole assembly is interchangeable, u just need 1 short stud or u could just run 9 bolts instead of 10.

Because the T-18 centre has one of the holes cast at a different length to the others, guessing its so u cant put the centre in the wrong way or something.

You could probaly just swipe an old stud out of an s-series and stick it in the T-18 housing.

Cheers
Paul

[indi]

Originally posted by RobertoX@Nov 10 2005, 09:29 AM
A database of this would be cool http://www.ae86drivingclub.com.au/forums/emoticons/wink.gif
You mean like this one.....

http://www.geocities.com/MotorCity/Pit/997...Drivetrain.html (http://www.geocities.com/MotorCity/Pit/9975/dataBySubject/Drivetrain.html)

[RobertoX]

Thanks Indi,
It doesn't really tell me what ones are found in which cars but the page that deciphers the axle codes is pretty good! I wonder where I can get a 7.64:1 ? http://www.ae86drivingclub.com.au/forums/emoticons/tongue.gif

[driftae86]

i have a jdm dash with adm diff ratios. which makes mine read under what im doing....not the best combo for cameras http://www.ae86drivingclub.com.au/forums/emoticons/tongue.gif

so i suppose the difference is 10%? handy to know

[skein]

I'm running a T-series rear, but even when I had S-series my speedo was always about 20km/h out. So speedo reading 50 means i'm doing 70.
It's about the same up higher, still 20km/hs out so I assume it's not a ratio problem, just needs to be calibrated.

[mc68]

mmk, say if you're running a jdm box, a electric dash and the 4.3...itll be fine, innit? http://www.ae86drivingclub.com.au/forums/emoticons/cool.gif

[crazy86]

Yep, sounds like JDM stock setup all round.

[RobertoX]

Just thought I'd give some confirmation on my question before, you can indeed get a 4.1 t series centre from an auto RA40. Went down to U pull today to get one and all the auto RA40s had them, t292 axle code...