Diff help for an ra28

**INSANE_PAINT** · 15-09-2009, 08:02 PM

just wanted to ask a quick question, hoping someone can help with.
i have an ra28 celica and wanted to upgrade the diff, i have a spare hilux 2wd 1992 model, i was going to get the diff out i'm pretty sure is the rn85 diff, but i noticed most people r using the rn25 diff or rn27. i'm sure there is a reason for this, so if someone can help me, i would just like to get all the useful parts i can off the hilux for the celica, just not sure if the diff is even useful to me, if the rn25/7 is better i'll just get one of those

-Vic

**timbosaurus** · 15-09-2009, 08:14 PM

the early hilux diffs (RN25 etc) are narrower. If I recall correctly, 1360mm hub-hub compared to 1410mm on the later ones.

The standard celica diff is 1370ish. (I could have the figures slightly out...)

So the later one is fine, but means you need to run FWD offset (~+35 to +40mm) rims on the back. Often this suits, as some front strut upgrades mean you have to run something similar on the front.

**INSANE_PAINT** · 15-09-2009, 08:29 PM

thank you sir,
i guess i'm getting the rn25 diff then, i love having dish.
thanks again for the quick reply also, i'll check the brakes tomorrow, or i'll do some research on the net to see if the front calipers are even usefull to me or not, or anything else i can take off it before i get rid of it.

cheers
-Vic

**timbosaurus** · 15-09-2009, 09:16 PM

hmm... what are the brakes for?

**INSANE_PAINT** · 16-09-2009, 10:36 AM

nothing, i thought i could use them but there pretty much useless, i'm just going to have to buy some 4 pot surf calipers, or maybe even some nissan ones like this other ra28 member ride i was looking at, haha awesome ride by the way.
i was hoping i could use something from the hilux but i guess theres nothing on it that i can actually use
-Vic

**timbosaurus** · 16-09-2009, 12:38 PM

haha... we'll i've changed struts again since then, and put those brakes onto s13 coilovers and bolted them in. Seems to work OK, but haven't measured bumpsteer or given it a hiding yet.

If you want dish, you could always use the later diff and shorten it while you're doing the mounts. and get mega dish

**INSANE_PAINT** · 16-09-2009, 03:33 PM

i would love that dish, but i'm not sure what wheels i'll be running yet, so i'm not to sure about the the backspacing will be yet, so ill just stick with the unshortened RN25 diff, i'm just going to keep it a little less complicated for now, eventually might go for a minitub though with a shortened diff, i'm going for the corona struts i think, 33 gtst brakes and discs.
Bought the car, then a week later a tree fell on in, so i thought, might as well start planning for the 1jz conversion and start stocking up on all the necessities.

-Vic