IRD Oil Level plug

Troops!

Having trouble getting IRD level plug undone, before I round the nut any further.....

Does anyone know the thread size of the plug? If all else fails with an impact socket then it will have to be a drill and retap

Whoever designed the outer case of the IRD should be shot

OK so perhaps nobody can help me with the thread size question??

What about this..... was down at my official dealers ordering up a new level plug for the IRD (for whenever I get the other one off), I asked for some of the IRD oil Texaco S5 75W-90.

I was told they only sell it in 25litre drums, they suggested using gearbox oil instead Texaco MTF94.Has anyone else substituted the oil for something else without any problems

I have heard on here somewhere that it has to be a specific oil, surely somewhere will have smaller than 25litre containers for sale.

Do not use MTF94 in ird unit!
Use only a good quality 75W90 synthetic gear-oil.
You need 1.2 lt

OK thanks guys.

Couldnt believe myself when the main dealerr suggested it. In fact it was the head technician who told the guy behind the parts desk that MTF would do the job.

Is it any wonder the components pack up before their service limit?

Hi I put in 75w90 and have not had any problems. The filling nut on the ird is not so much tight as hard to get at with any leaverage. i had to place a few pieces of wood against the chassi to leaver against. I found that attacking it from the back ( not directly under the sump guard) but from behind the front wheel was the best angle with a strong bar , extension and socket.

Whenever possible use a SIX-FLATS socket on tight nuts and bolts, not the common Bi-Hex 12 flat ones.

The 6 flat ones will bust the bolt before they round off the corners.

try-
ep hypoid gear oil semi synthetic 75w90

jms1 said:

Hi I put in 75w90 and have not had any problems. The filling nut on the ird is not so much tight as hard to get at with any leaverage. i had to place a few pieces of wood against the chassi to leaver against. I found that attacking it from the back ( not directly under the sump guard) but from behind the front wheel was the best angle with a strong bar , extension and socket.

Click to expand...

Tried every angle with the thing, using an extension bar on the rachet too. The extension bar meant I wasnt squarely on the nut and round three of the corners. Need to get out my 4lb club hammer after its been soaked in penetrating fluid for a few days.

CharlesY said:

Whenever possible use a SIX-FLATS socket on tight nuts and bolts, not the common Bi-Hex 12 flat ones.

The 6 flat ones will bust the bolt before they round off the corners.

Click to expand...

Using 6 point sockets, I have a 19mm spanner with off set shank on it, but cant get the thing on the nut squarely because of the design of the IRD casing. If I could get the spanner on squarely then I could crack it with a hammer.

I might hacksaw off the parts of the IRD casing to get access. They dont look structural... only there to annoy mechanics

Ok, so it hasent gone as planed. When using a wrench its important that the socket is squarley seated. However danmage done, lets move on. I would not cut the lips away.
As you will be changing the nut anyway, go down to your local garage and see if they could weld a second nut on to it. Then you would have better access.

jms1 said:

Ok, so it hasent gone as planed. When using a wrench its important that the socket is squarley seated. However danmage done, lets move on. I would not cut the lips away.
As you will be changing the nut anyway, go down to your local garage and see if they could weld a second nut on to it. Then you would have better access.

Click to expand...

Thanks.... my mate had offered to bring up his welding gear, certainly easier than drilling and tap which would introduce shards of metal into the IRD.......NOT GOOD!

There is a full machine workshop where I work, another option is to use a reverse thread tap with undersize bolt and try it that way. Getting hold of the engineer is the only problem as he has the keys and no untrained staff are permitted to operate the machinery (Usual health and safety). Some top brass kit in there

Well at least thats good news and hopefully a cheap solution. I did notice when i undid mine that there was a vacume in the IRD that as soon as i undid the nut a hissing sound was heard as air was sucked into the IRD. NOt sure if this is normal! However back to your issue. I would stay away from drilling and tapping as a final solution. When you are about to undo the nut, weather you have filed or welded (Probably the best solution is to weld), heat the nut up, as diffrent metals expand at diffren rates, this might ease the leverage required to undo. I suspect that the plug had been removed once befor and the sealing washer was not replaced when refitted. This is importand and that it is torqued at the right spec to avoid this type of situation.
Let us know how you get on

Well I have to admit defeat on this one.....

Yes; I can just see it now.... directors and designers of the project CB40 (Freelander) gathered round the board table.

Head Director - "Now make sure you use the cheapest alloy steel that you can find for the IRD level plug and then shove it in the most awkward place for access. Make sure its hindered by the subframe, bulkhead and steering rack, that'll p^ss a few people off"

Head Designer - " Consider it done boss"

Head Director - "And while you are at it make a horlicks of the IRD ratio, 0.8% that ought to be enough to mess it up completely"

Head Designer - "Yes boss"

Head director and designer ..... this cup of malt drink is just for you... thanks ever so much

Here are some pics of a new IRD oil level plug, its made from that cheap alloy steel, looks pink and tarnished under bright light. Same stuff the tools are made of that you get free with flat pack furniture.

Its not even precision made, just over 19.4mm/0.75" at the flange.

Its a short arse stubby plug. Thread is about M18, talk about oversized.

The core of the plug is bored with only 10mm of steel, internal bore diameter is 14mm.

I drilled the new plug with a cordless 14V drill, 7.5mm bit , it was a s soft as pie Then tapped with M8 thread.

Will do the same with the old level plug on the IRD, a few shards of soft metal shouldnt cause any harm inside the diff. A M8 bolt with some PTFE tape will seal it up again good and proper

I dont understand why you are making a hole in the new plug? If you are drilling out the old one, there is a trick to minimize the loose chippings falling into the IRD. Place some multi purpose grease on the drill bit. This will help the chippings to stick to the drill bit and avoid falling into the ird.

jms1 said:

I dont understand why you are making a hole in the new plug? If you are drilling out the old one, there is a trick to minimize the loose chippings falling into the IRD. Place some multi purpose grease on the drill bit. This will help the chippings to stick to the drill bit and avoid falling into the ird.

Click to expand...

Cheers, yes have the lithium grease ready.

I drilled the new plug to see how easy or difficult it would be, it was too easy... a trial run if you like.

I bought the new plug with anticipation that the old would eventually come undone... no such luck.

Tried all of the suggestions with extension bar, levers, block of wood but that plug is seriously bonded and corroded to the IRD

I thought about welding the nut on top of the old one... but there is a chance that the threads on the IRD could strip. I dont have a tap that wide

and it seemed like such a simple job. Check the oil.
I have been thinking of checking mine for a while. dont think I will now.
Best of luck

aussielander said:

and it seemed like such a simple job. Check the oil.
I have been thinking of checking mine for a while. dont think I will now.
Best of luck

Click to expand...

You never know Aussie, you might have more luck than I did.

Winter driving when roads are covered in salt spray doesnt help. All surface integrity of the metal goes to pot

Well its complete.

Drilled old IRD nut insitu with M8 thread, pic below, spot the rounded corners! Dont be deceived by the pic, it looks spacious but it isnt.

Had to disconnect RHS of anti-roll bar and drop link just for that extra 2cm of space to position the drill squarely.

I correct myself about the Bosch 14v drill, it was only 12v...says it all really, a puney 12v drill can make short work of the cheap steel bung. A mini compact drill would have been even better.

Drained the oil, no problems removing the drain plug, usual 'crack' and it was free. I noticed there was a magnet on the IRD drain plug to catch any shards, not too many. The IRD oil was filthy and only a few flakes of metal from normal wear and tear.

refilled with Carlube EP90 Hypoid gear oil (Nissan Skyline boys are using this stuff in Limited slip diffs) , you'll need 1.1 litres

This morning whilst driving to work the transmission was slightly quiter and smoother on acceleration. Felt like new

good one LR - any reason why you only went for an 8mm hole - or was that the largest you could practically do? Did you try applying heat to the plug to expand it in the casing first??