Matteybean Posted April 7, 2015 Share Posted April 7, 2015 Hi guys I started looking into getting my diff shortened .. need it shortened 30 mm each side letting me fit my 9" rear wheels inside factory wheel arches without the need to modify.. Now 25mm would prob do it n roll guards .. I spoke to "diffs r us" in Otahuhu he said something along the lines off diff is too small if he cut that off each end it woulf cut most of spline out and would cause me problems in future broken axles etc.. He said he can do it but wouldn't guarantee his work n if some ting went wrong in future it wouldn't be his problem lol ... not keen on forking out 1000 for him to shorten it n crap out. Now I do have 2x rt104 diffs how hard would it be to tackle on my own or is anyone keen on helping / doing it Cheers Quote Link to comment Share on other sites More sharing options...
kpr Posted April 7, 2015 Share Posted April 7, 2015 pull the axles out and see how much spline is engaged into the the side gears of diff head. usually there is some spare spline further up the axle. dropsaw the spare amount off the ends, shorten case same amount. can usually only get 10-15mm per side out of them. which is why mr diffs are us is saying, 30mm is not gonna happen otherwise you need to spend the money getting new or modified axles Quote Link to comment Share on other sites More sharing options...
Matteybean Posted April 7, 2015 Author Share Posted April 7, 2015 Don't have a clue what any of that means lol . Getting 10-15mm would help em fit that little bit easier tho .. if it's not worth it I'll just end up paying someone to make the wheels fit under the guards. I checked clearances n there is room for it to fit just don't have a clue how Quote Link to comment Share on other sites More sharing options...
Seedy Al Posted April 7, 2015 Share Posted April 7, 2015 Don't have a clue what any of that means lol . hmmm........ maybe you shouldn't be doing this your self then........ 4 Quote Link to comment Share on other sites More sharing options...
cletus Posted April 7, 2015 Share Posted April 7, 2015 Is the car going to end up with more power? Now would be a good time to upgrade the diff if so Tony at steelie gears just down the road from where you went is better at diff stuff. Quote Link to comment Share on other sites More sharing options...
Seedy Al Posted April 7, 2015 Share Posted April 7, 2015 so far I think has been talking about going from an 18r to 18rg so a 30 hp gain. probably not worth an upgrade. Cant even think what type of diff is in these T series? 1 Quote Link to comment Share on other sites More sharing options...
Matteybean Posted April 7, 2015 Author Share Posted April 7, 2015 Hey thanks for Your replies . @seedy yeah that's why I said in my post anyway wanna give me a hand/show me what to do . Like I said I have a spare diff if I fuck it up I've got a mig welder n lots of room. Yeah what I've read there are 2 different diffs . A t series and F Series ?? Depending on year of the corona mines a 78 I'll take it apart n that'll help me get my head around what you'll saying lol. Yup 18rgu being translated in. I don't think I need to go extreme n upgrade diff yet lol .. i needed a w50 gearbox for my 18r then found a 18rgu complete with w50 box hence why Im upgrading . I do have a driveshaft which was off a manual collumn shift rt100 weather itl fit I guess I'll find out . This gives u an idea of how much it needs to go in . Note the tread is currently under the guards they r 185/55/14 on a 9" I'll be putting legal tyres on it or atleast close to it these were just a teaser 1 Quote Link to comment Share on other sites More sharing options...
R100 Posted April 8, 2015 Share Posted April 8, 2015 Give karlos at steel surgeon a call. Last diff I had shortened up was when I had a commodore head fitted to an escudo housing. He cut and welded the axels. Cost $450 all up. Worked a treat. Did lots of burnouts with that diff. Infact every time I took off I did a skid in it. I only lived 5ks from work and I would use 3 sets of tires each day just getting to and from work. That's how strong the diff was. Pretty strong eh. 3 Quote Link to comment Share on other sites More sharing options...
Seedy Al Posted April 8, 2015 Share Posted April 8, 2015 do your cars have a factor spec tag on the fire walls, the silver tin one down near the bottom will be a transaxle number. will start with a T or F and have 3 numbers after it. this tells you want diff it is. Think My Cressida with 18r is E series of all grossness 1 Quote Link to comment Share on other sites More sharing options...
Adoom Posted April 8, 2015 Share Posted April 8, 2015 I think the diff(T-Series) I had shortened 25mm each side was from a corona. The problem with the original axles was that the diameter decreased just after the spline, so if you shortened it and cut more spline further down the shaft, part of the spline "teeth" will not be the full height. Is that the problem you have? I managed to find some axles from a different toyota at Pick a Part, that were a few mm larger diameter overall but same bearings, same number of splines and even 10-15mm shorter than my original ones. They machined that old spline diameter down and cut the new spline. I can't remember what I got the axles from though, it was 10 years ago. It was a Toyota something Wagon.... According to this: http://www.toycrazy.net/tech/diffcompare.html It might have been an E-Series axle. The GX61 wagon looks right. 2 Quote Link to comment Share on other sites More sharing options...
smokin'joe Posted April 8, 2015 Share Posted April 8, 2015 haha, is that ^ a photo for rust repair cert!!! 1 Quote Link to comment Share on other sites More sharing options...
johnny.race Posted April 8, 2015 Share Posted April 8, 2015 I think the diff(T-Series) I had shortened 25mm each side was from a corona. The problem with the original axles was that the diameter decreased just after the spline, so if you shortened it and cut more spline further down the shaft, part of the spline "teeth" will not be the full height. Is that the problem you have? I managed to find some axles from a different toyota at Pick a Part, that were a few mm larger diameter overall but same bearings, same number of splines and even 10-15mm shorter than my original ones. They machined that old spline diameter down and cut the new spline. I can't remember what I got the axles from though, it was 10 years ago. It was a Toyota something Wagon.... According to this: http://www.toycrazy.net/tech/diffcompare.html It might have been an E-Series axle. The GX61 wagon looks right. Yeah this ^ I know a little bit about axles and stuff. Near all OEM axles step down after the spline for a short distance. The only way to respline in this area is to have it built up with weld first. Check out trader_84 on TM. His TM ad for resplined Hilux axles explains somethings about the axle resplining process. I know T_84 because I'm him and those pics of axles were taken out the back in my shed. I've never done a T series diff but are they the same as a Lite Ace or something? I got one here as well as some F series ones I am trying to unload. I was going to tool up to offer them in shortened form but it seemed too much work for the perceived return, so have just stuck to Hilux, BW78 and 9 Inch diffs. They are all 90 degree included angle stuff. I am not equipped for 60 degree spline cutting and don't intend to be. The other thing you need to watch out for is going to big arsed axles and then having to take too much off the diameter. Near all OEM axles are case hardened meaning its hard on the outside and like butter on the inside. I know how deep the various OEM axles are hardened to, and have examples of each type of axle i cut. I cut cold and stay well within the hard area so there is no need to pay for re-hardening. Putting a smaller diameter spline on a large OEM axle will see you removing all of the hard casing and working within the soft core area necessitating re-hardening. This is expensive and IMHO is hit and miss at best. Cheers. 1 Quote Link to comment Share on other sites More sharing options...
Matteybean Posted April 8, 2015 Author Share Posted April 8, 2015 Cheers for info all. Karlos from steel surgeon will do it n guartanee his work he has shortened t series diffs before up to 25mm with no problems !! Will take diff out this weekend n get it away to him monday 25 mm would prob Be pretty close Quote Link to comment Share on other sites More sharing options...
R100 Posted April 10, 2015 Share Posted April 10, 2015 Maybe even go a little narrower. You can always buy spacers to space the rims out, but spacers to space them in are very rare now days. 2 Quote Link to comment Share on other sites More sharing options...
Ghostchips Posted April 10, 2015 Share Posted April 10, 2015 Is it possible to shorten a shaft by heating it at the place you want to expand it while pressing it? It would need re-hardening then huh? Quote Link to comment Share on other sites More sharing options...
sr1600 Posted April 10, 2015 Share Posted April 10, 2015 You would burn your fingers..... Reality is you would end up with something that doesnt run true even if you could manage to do that...... 1 Quote Link to comment Share on other sites More sharing options...
johnny.race Posted April 11, 2015 Share Posted April 11, 2015 Cheers for info all. Karlos from steel surgeon will do it n guartanee his work he has shortened t series diffs before up to 25mm with no problems !! Will take diff out this weekend n get it away to him monday 25 mm would prob Be pretty close Looking at this pic - 25mm overall meaning 12.5mm out of each side is going to make little difference aye? (That's if i understand it right) Try dropping a plumbob or some weighted string against the outermost part of the rim and measure from the string back to the guard lip. This measurement would be the minimum each side would have to move in to be WOFable(?) I don't know what he would be charging you to take an inch out but what ever it is - you would have paid it and still had a diff that would not pass a WOF when fitted with those rims. Maybe i am missing something, lol! Ask him to show you the jig he is going to use to ensure alignment of your diff is maintained. If it does not contain as part of it - a ke70 pumkin/carrier with dummy bearings as part of its makeup,then get him to explain to you how his work can be verified as being what you paid for. 1 Quote Link to comment Share on other sites More sharing options...
Matteybean Posted April 11, 2015 Author Share Posted April 11, 2015 hi. @Johnny nah 25mm each side mate 50 mm overall . Yeah I used my long level on the outside of the rim (it sits plumb) and measured it was 30 mm . Those guards haven't been touched and I'm happy to massage em out abit if I have too. Yeah I'll be getting him to shorten it as much as possible .. the 25 mm came from him previously doing so.. weather or not it's possible to shorten more i guess I'll find out Monday. Diff comes out 2m ... far to hung over to do it today pendulum rocked my socks last night Quote Link to comment Share on other sites More sharing options...
Seedy Al Posted April 19, 2015 Share Posted April 19, 2015 So did you get your diff shotertend in the end? 1 Quote Link to comment Share on other sites More sharing options...
JoKer Posted April 19, 2015 Share Posted April 19, 2015 So did you get your diff shotertend in the end? I think the results here //oldschool.co.nz/index.php?/topic/47993-sacked-car/ 1 Quote Link to comment Share on other sites More sharing options...
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