Ben Sale's white 1990 NA6

[bensale]

Thanks, I was too Dave =)

Haha, thanks Alex =) But I think it'll look better on your car! Besides, I think I may have seen that guard somewhere before... wasn't quite the right colour for my car!

[NitroDann]

I've got a spare guard you can have =P

Now THATS what friends are for.

Dann

[bensale]

Yeah, Alex is pretty awesome like that. . . =)

Today was diff day... As you'll read a few pages back I have a need to put the original diff back in the car and besides it was probably a good thing to do as the diff as it was leaking from the left seal and making a bit of a mess under the car. When i was talking to some people at the club committee meeting about needing to do the swap it was suggested I should take a few photos and do a write up for the club mag. I figured I could do the draft here for anyone is looking for a guide.

I apologise in advance and am a little embarrassed by the amount of mud on components in the photos... The joys of a motorkhana in a muddy field.

After having done the swap myself and swearing never again this time I was lucky enough to have CheyneX5 giving me a hand. Aside from turning up to my house with coffee and taking a lot of the photos it was fantastic to have him helping, especially when it come to putting the diff back in the car and in saving me from getting out from under the car... Much easier than doing it alone, thanks so much mate!

The first step is pretty simple, get the car jacked up. You want to do this properly as you're going to be working under there for a long time... I had wheel chocks at the front, jacked the car up by the diff and then had stands on each side. This is really the minimum requirement for this job. Before you jack the car up crack off the wheel nuts as you'll need to remove them later.



The next step is to remove the exhaust. As my mid pipe and muffler can be separated this is quite easy to do on my car without removing the chassis bracing, if you have an OEM exhaust and factory or aftermarket bracing you'll probably have to remove that too. If the exhaust hasn't been removed on your car before using silicone spray on the rubber hangers works wonders.



The next step is starting the epic un-bolting process. There are four bolts connecting the diff and tail shaft on each side and another four connecting the half shafts. You have to have the handbrake engaged to loosen the half shaft nuts. You can't access all of them at once so you have to take the handbrake off to rotate the shaft to allow access to the other nuts. Similarly to undo the tailshaft nuts you have to have the car in gear, but to access all of them you have to put the car into neutral to rotate the shaft. Having a second person save a lot of time here as you don't have to get out front under the car six times.




The next step is removing the half shaft from the diff. Remove the rear wheels... The trick to doing this is unbolting the top mounting bolt for the hub and loosening the bottom one allowing the hub to sit at a 45 degree angle. This pulls the half shaft far enough back that they are easy to remove from the diff. You might find the bolt holding the hub on in a bit hard to remove, I just tapped it out with a punch which was quite easy. Once you've removed the shafts from the diff it helps if you move the half shafts out of the way. I got Cheyne to cable tie them to the upper control arm.




Next you'll need to remove the bolts which connect the diff to the PPF. They have a 17mm head and are extremely long and can be hard to remove if they've been there a while. You'll also notice two 14mm bolt heads on a little block connected to the diff and the PPF. Unbolt these too as otherwise you won't be able to pull the diff out of the PPF.



The next thing to remove are the bolts which actually hold the diff cradle to the car. Before you do this you should make sure the trolly jack is under the diff to support it when you undo these bolts. The Diff will still be held in by the PPF too, but you don't want to put all the weight of it on the PPF. An extension bar is handy for this step. As well as the two main bolts you'll also have to remove two 12mm nuts which hold the bush in place. The second photo is carrier with the bolt and bush removed.




The next step is to get the damm thing out of the car... I hate this step. Basically you need to lower the diff and then slide it backwards out of the PPF. It's easier said than done and will take a bit of fiddling as it doesn't want to come out as the diff is practically fused to the spacer in the PPF. I found sliding each side backwards and forwards easing it out of the gap worked best. Be mindful that when you do get it free of the PPF it will drop and it is heavy, so be careful. When it's out you can smile..!

The next thing you need to do is remove the spacer in the PPF which will have stayed there when you removed the diff. It has two holes which the long bolts go through and the hole towards the front of the car has a press fitting which holds the block to the PPF. The only way I could think to remove this was with a hammer... Clarkson would be so proud..! Basically I tapped the rear of it to pivot it around and then tapped it up until I popped the spacer out of the press fitting. Then what i did was hammer the press hitting down enough so that it was sitting flush with the PPF, but not enough to remove it. In the photos the first photo shows the spacer and the second shows the PPF without the spacer. In both you see the press fitment sitting as it should after you hammer it flush.




The next step is to fit the spacer to to diff you are installing and fasten with the bolts you removed from the old diff earlier. I then drained the diff oil out of the diff I was putting in as I wanted to put fresh oil in and to make it lighter to lift. One trick when doing this is to undo the filler plug before you undo the drain plug as you don't want to drain all the oil out if you can't put any back in because of a seized bolt!



Putting the diff back in is a simple matter of sliding it back into the PPF. Sounds easy... Not really. This where it really helps to have a second person to help get the positioning and angle of the diff right to slide it into position. Once you get it in place get the trolley jack under there to support the diff and save your arms. I first put the bolts back into the PPF and then tapped the press fitting back in. Next was the bolt up the chassis mounts at the top of the cradle. When those bolts are in you can remove the trolly jack.

Re attaching the hub is quite easy, the trick is to raise the whole assembly up by the LCA with the trolly jack and then bolt it back up.




From here you simply re attach the half shafts and the tail shaft and fit all the nuts and bolts. Installation is the reverse of removal =) I have developed a habit with my car after having numerous issues with seized bolts that everything I take apart gets put back together with a good coating of copper grease. Works wonders =)

Remember to put some oil in the diff... It's quite easy to forget, I nearly did and I know of one case where a friend of mine destroyed a diff because they forgot. Fill until oil starts to dribble out of the filler hole.



We put the wheels back on the car and I decided to run the car very gently while it was still on the stands before putting the exhaust back on to test everything was working properly. As it was I then re attached the exhaust, checked everything was tight, dropped the car, checked the wheels and we were done!



I hope this guide can be of use to anyone looking at doing this job. Theoretically all the information here should work for someone looking to swap over from an open diff to any form of LSD also.

[de Bounce]

Excellent write up
Always easier the second time and much more fun with a friend to help out.

[emexv]

Great write up Ben and a job well done. I hope there isn't too much permanent damage from the moron who hit you car.

[-alex]

turning up to my house with coffee and taking a lot of the photos

hehehehehe and using a hammer

[bensale]

Haha, Cheyne may not have most, umm, conventional method for cleaning mud out from the guards... It was amusing to watch though... and it has to be said effective too! I should have got him to give the springs and shocks a proper clean too... Perhaps not with a hammer though

And thanks guys, hopefully it helps anyone out how wants to do this. And yes, while you can do it yourself a second person makes it much easier =)

[CheyneX5]

turning up to my house with coffee and taking a lot of the photos

hehehehehe and using a hammer

And a mighty fine job i did! I should also mention that i was not bashing the car with the hammer, just lightly lifting mud off wit the hook side of the hammer.

Still didn't stop dirt getting in our eyes when fitting the diff though.

Good job Ben, i had fun helping!

[bensale]

The mental images that go with you using a hammer to remove mud from the guards are so good. Why did you have to remove them with a description! =P That dirt was no fun... I wish I wore some glasses. Thanks mate =)

[de Bounce]

I gave mine a quick clean on the Monday after the Motorkhana with a pressure cleaner.
Started doing a wheel change on the Tuesday and found more mud in and around the suspension.
I ended up removing each wheel and cleaned everything I could reach with a pressure cleaner.

Might be worthwhile as I removed about 2kg of mud from under mine.

[bensale]

This afternoon I replaced the two front shock bushes. In order to do this I had to remove the front shocks so I thought I'd do a quick photo guide to that too.

Firstly don't follow the guide in the Haynes manual... If you do you'll stuff up your wheel alignment like i did on the first side I did when you loosen the LCA bolts... And stupid me didn't think to mark anything either... You don't actually need to touch the lower control arm at all... It's been about 18 months since i fitted my suspension so I forgot this...

First step is to jack the car up safely (I always find the front a pain due to how low the car is and the lip) and put it on stands, remove the undertray, then disconnect the swaybar from the endlink. I also unbolted it from the chassis so I could move it out of the way of the control arms.




Next undo the two nuts in the engine bay at the top of the shock.



Then remove the bolt at the base of the shock.



Next remove the long bolt which runs between the two bushes on the upper control arm. Before I removed this I placed the scissor jack underneath the lower control arm. This is because when you remove this bolt the whole assembly will drop down quite suddenly when you get the bolt out. The long bolt is also a lot easier to remove when the hub and control arm is supported, if it is not supported you'll probably find you need to use a punch to remove it.




Then lower the control arm down via the scissor jack (you could use a trolly jack but i only have one and i decided to leave it for additional support under the car. When you've lowered it enough you will be able to pull the shock out.

And here is my bush... No wonder it was making a lot of noise...



The process of removing the actual bush was a lesson in using the right tool for the job... I stuffed around for ages trying to remove the bush using various unsuccessful methods... I just didn't have the right tool. I remembered that the MX-5 club actually own a bushing tool and President Murray Finlay is the custodian of that tool and happens to live five minutes down the road from me... So a quick drive in the Alfa to his place... Once back it took me literally two minutes to pop the bush out.



And to put it politely the bush was stuffed.



Installing the new bush in the shock is quite simple with a vice. I put a bit of grease on then first popped the bush part in. I then got the metal sleeve insert and put in in the same way with the vice. It took about a minute of fiddling to get it all to sit correctly



And then back together it all goes. As always I applied a good amount of copper grease to all bolts which I had removed before I put them back in and I also cleaned it all up a bit. Like Bob I found an obscene amount of mud under the car, this in-spite of going to the carwash and high pressure hosing it down after the motorkhana.



The other side was the same as this, with the right tools, preparation and without any problems I would say you could do this job in under two hours start to finish. This guide will work for anyone installing new front suspension too =)

[CheyneX5]

Fantastic Ben!

Does it feel any different?

[Okibi]

Nice write up, that's the same way i've always removed the shocks, think I got the technique from Keith Tanner's book.

[bensale]

I've only dríven it around the block as the alignment is way out on the front right... I'll try and sort that out tomorrow. It didn't make any noises though =) The one thing i did notice was that it felt like I had power steering as I also fitted my new tyres!

Thanks! It's a really quick and easy technique, so much better than the way the Haynes manual says to do it (loosen the LCA bolts and lever the it down). Once I remembered what I was doing the second side took maybe 5-10 minutes to remove the shock =)

[surok]

nice work ben!
because of your valiant efforts, i will give replacing my bushes a go.
seems easy with that tool. i think my mechanic has one.
and thats a f**ker about being sideswiped! that really sucks.
but its good that you were able to polish out the scrapes pretty well.