Front Diff troubleshooting / questions

cuzza_wa
Been here a while
Posts: 105
Joined: November 20th, 2017, 2:54 pm

Front Diff troubleshooting / questions

Unread post by cuzza_wa » February 12th, 2018, 11:14 am

Hey all,

Have been rebuilding the hubs on a 1988 hilux ln106 solid axle 4x4 and upon putting everything back together noticed as issue with the front diff / driveshaft.

Basically in short, got the swivel housings back on and CV's in, and noticed the LHS axle / CV turns the front driveshaft (had set both free wheeling hubs to "FREE" before dismantling) but the RHS axle / CV (short one) doesn't turn the driveshaft at all, and makes a scraping metal noise similar to a dragging brake. The CV is also touching the inside of the CV housing - it wasnt doing that before i pulled it out i dont think.

My first guess is my front diff is shot, but does anyone know what exactly it is that has gone?
If i need to replace it, can i put an LSD from a rear axle into the front?

Thinking it might be a day down the wreckers getting another front diff.....a ute arrived there last week, likely a LSD rear in it and 4.3's too.

Thanks for any help guys.

Cuzza

Peter Aawen
Admin
Posts: 20795
Joined: June 17th, 2005, 8:01 pm

Re: Front Diff troubleshooting / questions

Unread post by Peter Aawen » February 12th, 2018, 12:42 pm

Sounds like you might not have got the RHS axle/CV engaged properly with the side gear inside the diff, hence the noise etc & the CV touching the housing... is that CV sticking out just a little more than the other side?? Maybe anything from about 10 to 18mm or so?? That'd be about how much the spline on the diff end of the half-shaft isn't fully engaged/pushed into the side gear spline.... & if that's the case, that'll be where the noise is coming from!! :gurn:

You might need to put some gentle pressure on the RHS end, pushing it gently in towards the diff, while someone else turns the LHS CV or axle half shaft, in the hope that by introducing some rotation into the diff centre, the gentle pressure on the RHS will let the half-shaft spline slip into the side gear spline.... could need a bit of 'on then off then on again' pressure; or you might also need to add a fractional rotation to the RHS as well, so you can get the splines to match up & (eventually??) let the splines engage so that the half-shaft slips right in to the side gear & the CV ends up in the correct place in the middle of the swivel hub....

Or maybe I'm barking up entirely the wrong tree!! :petrified: :o

There again, what sorta deal will the wrecker do for you on the entire fr/rear diff, axle, housings, hubs package etc.... if the gearing's a better ratio for your needs & the LSD actually works (probably not worth too much benefit if it's an OE LSD that's done more'n about 40,000 km without a re-pack tho!) & everything else is in good nick, then it might be worth swapping?! Your call on that!

Good Luck! ;)
An Ex-Service person is someone who thought enough about their country & how great it is, how lucky we are to live here, to write a blank cheque made out to 'The People and Commonwealth of Australia' for the value of 'Up to & including my Life!'

cuzza_wa
Been here a while
Posts: 105
Joined: November 20th, 2017, 2:54 pm

Re: Front Diff troubleshooting / questions

Unread post by cuzza_wa » February 12th, 2018, 4:16 pm

your first theory sounds like it might be my issue, well at least i bloody well hope so!
The LHS one was tricky to get in and involved me putting the RHS in and moving the driveshaft so i could actually engage it, seems strange since i did the LHS and then the RHS that now the RHS does not engage - but given what you said it is worth triple checking before heading to the wreckers. Will take some measurements tonight.

Wreckers is ok, i spoke to the guy who dropped the ute off before it went to the wreckers, and he gave it to them for free so i have some bargaining power there, although the ute is rusty as anything.
I've just re-built my hubs and re-painted it so i don't want to swap now or i lose my hub kit and nice black knuckles :)

Thanks Peter!!

cuzza_wa
Been here a while
Posts: 105
Joined: November 20th, 2017, 2:54 pm

Re: Front Diff troubleshooting / questions

Unread post by cuzza_wa » February 13th, 2018, 9:42 am

Ok turns out i had the axles pushed too far in.

I pulled both sides out as much as i could (i have the spindle on, but not the hub / disc) and measured and they were both the same from end of spindle.......then turning RHS would turn the LHS in oppostie direction, and driveshaft was not turning, and the noise was gone - bingo!

i was being far too cautious, probably could of just carried on re-installing everything and checked properly once i had the hubs on in hindsight.

Peter Aawen
Admin
Posts: 20795
Joined: June 17th, 2005, 8:01 pm

Re: Front Diff troubleshooting / questions

Unread post by Peter Aawen » February 13th, 2018, 10:22 am

It never hurts to be sure to be sure! ;)

Glad you got it sorted tho. :thumb:
An Ex-Service person is someone who thought enough about their country & how great it is, how lucky we are to live here, to write a blank cheque made out to 'The People and Commonwealth of Australia' for the value of 'Up to & including my Life!'

Return to “HiLux”