1.8 diff upgrade install questions

[StockNA]

Hey guys I'm changing diff over to a 1.8 torsen 2. I have watched a few videos, and read a couple threads on it, but I still have a few noob questions.

1. Do I need to put grease on the drive shafts before I fit them into the diff, if so which grease? I'm assuming that they work of the diff oil, but figured I would ask.

2. What's the best way to unpinch the driveshaft nut? I think I just need a bigger hammer but any other ways or tricks would be nice to know.

3. Best way to stop the gearbox oil pouring out whilst the tailahaft is out?

4. Do you need to completely remove the ppf? I've seen and read two different opinions on this

5. Ways to remove diff bushes? Also which grease should be used to fit delrin bushes in?

6. Other than the obvious main items, anything else that should be replaced whilst doing this?

7. Anything else? Tips, tricks, hints or problems people have encountered whilst doing this?

Thank you

[Mr Morlock]

Did you read a repair manual- they are supposed to describe the procedure.

[hks_kansei]

Hey Evan, a few answers below. Enjoy!

Hey guys I'm changing diff over to a 1.8 torsen 2. I have watched a few videos, and read a couple threads on it, but I still have a few noob questions.

1. Do I need to put grease on the drive shafts before I fit them into the diff, if so which grease? I'm assuming that they work of the diff oil, but figured I would ask.

Grease the shaft ends up so they don't grab the shaft seals and rip them.
type doesnt really matter, even oil works fine just hard to keep it on without it coming off. I'd use whatever grease you have around.

2. What's the best way to unpinch the driveshaft nut? I think I just need a bigger hammer but any other ways or tricks would be nice to know.

Hammer and a screwdriver (or cold chisel if you've got one) just belt the indented part back out, it shouldnt take that much force.

3. Best way to stop the gearbox oil pouring out whilst the tailahaft is out?

Drain the gearbox first.

4. Do you need to completely remove the ppf? I've seen and read two different opinions on this

no, but might need to loosen the gearbox end to make it easier to line us those stupid farking spacer things

5. Ways to remove diff bushes? Also which grease should be used to fit delrin bushes in?

Hydraulic press, or a vice (harder)
if not, fire, burn them out.

6. Other than the obvious main items, anything else that should be replaced whilst doing this?

check the PPF alignment after, apparently can cause driveline shake if out of alignment,
Go over all the nuts and bolts a second time after doing it, saves missing one and dropping a bolt.
Loctite the PPF long bolts, they vibrate and fall out (had it happen, sucked)

7. Anything else? Tips, tricks, hints or problems people have encountered whilst doing this?

The axle nuts will be hard to remove, as in almost impossible.
you'll need a BIG drive socket for them, probs 1/2inch min, anything smaller you'll break (grab a 3/4 if you can)
you'll also need a long arse pipe to give you leverage, i've got a 5ft long steel pipe for this purpose if you want to borrow it (might be at Craigs place, can't remember if I picked it back up?)

Thank you

[StockNA]

Nik, thank you, I knew I should have asked you from the start

[StockNA]

Morlock, firstly asking for real life first hand experience, which include real world problems and issues. Secondly why would I have a repair manual for a car I don't own? I own an na6 not an nb

[ralt]

Hi.
Hmm morlock is right there is virtually no differences between the models when doing this job except for........
You will have some challenges if your NB diff housing does not have the spacer in the diff carrier. These are usually removed if the housing comes from japan. They remove them and sell them as scrap. The reason the NA spacer will not fit an NB is a vertical rib in the casting of the NB which prevents the NA spacer being fitted. If this is the case knock the spacer out of the NA carrier it has an insert for the front ppf bolt. Knock this insert out of the spacer and simply fit it to the NB diff carrier along with the locating ring which locates the bottom spacer which bolts on the bottom of the carrier. On the NA it uses one bolt to attach it the NB has two therefore you can only use one bolt.
No need to remove the ppf after you have removed the two long bolts and have the housing supported get your jack and place it against something on the left hand side and wind against the ppf but only until it just clears the diff carrier you will not bend the ppf.
Also there is no need to remove the spacer in the top of the ppf or the nuts as it is an interference fit and for that reason best left where it is.
The tailshaft is left in place in the gearbox until the job is done and then jack the car up in the rear high enough for the oil to flow to the front of the gearbox and fit the replacement tailshaft.
Be prepared getting the axles out of the hubs usually the right hand side will come out ok the left hand is always a problem because we dive on the left and this side gets more water etc which rusts the splines in the axle. If you have problems it usually means a press and an oxy torch to get it out of the hub. Hope this helps and have fun.

[StockNA]

As much as morlock may be right it's the things that yourself and hks_kansei have mentioned that I wanted to know. Thank you for the advice

[hks_kansei]

The manual is good to have, but it also assumes you are a qualified mechanic (well, the Mazda one does)

It also assumes you have full access to a hoist, every special service tool, and that you'll be replacing every item it says.


For example, the Mazda workshop manual I recall has a line about how if you remove the PPF then you should replace the whole thing. I have no idea how they decided on that, but yeah.

The manual also tends to give the long way around for things when in real life there can be shortcuts (for example, removing shocks. Just remove the top control arm bolt and lever the assembly down to remove the shock, the workshop manual says to remove the whole knuckle first..)





So yeah, the Manual is great to have, but it's great to have in conjunction with talking to people who've done it in real life.

[StanTheMan]

the whole idea of these forums originally was so you don't have to have the manual.

Ive done virtually everything on my NA6 without manuals. Plenty of Info here & the big forum. Questions like this bring Community together.

I suppose times change. The rise of the forum warriors for internez is well & truely here.

I changed my Diff almost a decade ago. I recall removing the the drive shaft nuts was a major pain in the backside.
In my case, I used a massive 1200mm extension . A pipe I happen to have lying around. to get it to actually move. An 85kg person (CraigyBaby) virtually had to jump on the end of it.
Other former members actually drove their cars to a tire place & got them to undo that nut with a rattle gun. That worked a treat but they drove it back to thier place very gingerly. There is risk involved with doing stuff like that. But it worked. Its your call.

I don't recall having an issue with oil coming out of my gearbox when the shaft was removed. It would have been a major battle with the wife if here was a big puddle of oil on the driveway. I had patchy raised on car stands. Perhaps it was only raised at the rear I just can't remember. But if you want to be sure drain the oil.

I changed a NB8A Torsen 2 into an NA6. I do recall that washer. but cant remember much about it. memories have gone a little grey.

The one issue I had was lifting the diff back into place. I barely had enough strength. But managed with help. Thanks Craig all those years later.

[StanTheMan]

& speasking of community.
This is when we had a bit of a dodgy day.....changing all my bushes in Patchy.















This was all done without a manual. Lots of info from all sorts of sources. But brought together by various forum members.
Nothing wrong with StockNA's question.....in fact I encourage it.

[hks_kansei]

I recall removing the the drive shaft nuts was a major pain in the backside.
In my case, I used a massive 1200mm extension . A pipe I happen to have lying around. to get it to actually move. An 85kg person (CraigyBaby) virtually had to jump on the end of it.
Other former members actually drove their cars to a tire place & got them to undo that nut with a rattle gun. That worked a treat but they drove it back to thier place very gingerly. There is risk involved with doing stuff like that. But it worked. Its your call.

I had the same issue, but at the time didnt have any pipe handy.
I put the socket on the nut, had the longest breaker bar I had on it, then put the jack under the handle and lifted expecting the weight of the car to be plenty......

turns out all I did was lift the car up with the bar...


I ended up just dumping my car at the workshop and got them to do the whole swap since I needed the car later in the week and ran out of time to DIY