Crown wheel & Pinion Replacement

[Alex Roux]

After hearing the "humming" sound at the back, I was told by Mayfair gearboxes that my Crown wheel & Pinion needs to be replaced.
Now I understand that there are two different sizes of these, namely the H233B and H260. The latter is apparently stronger and used for the 4.5 and 4.8 Patrols.

My Patrol used to be a 3TD which had the hand grenade. Having converted it to the Lexus V8 (after much debate on this forum), it behaves much more like a 4.8, except of course it is lighter on fuel!
So now I wonder whether the H260 would not be more suitable than the H233B, if indeed possible? (I still drive with 265/75 on 16 inch rims, but may at some point want to introduce the 285s.)

[Tinus lotz]

Witch gearbox are you running with that engine?

[Peter Connan]

Alex you cannot put H260 innards in an H233 casing.

The 260 and 233 refer to the diameter of the crownwheel. So if you wanted to convert to H260, then you would have to replace the whole axle.

I was also under the impression that the H260 was not used in the 4.5, but only in the 4.8 and the Bakkie. But even though the basic number is the same, the axles are not. The axle in the bakkie is of fully-floating type, whereas the axles in all the wagons are only of the semi-floating type. Also, since the bakkie has leaf springs, all the brackets would have to be cut off and new ones welded on. Further, the bakkie has an LSD and not a diff lock, so in my opinion this is nat a very good swop.

That leaves you with a 4.8 axle, but these have got handbrakes built into the brake drums while your car has the handbrake on the back of the transfer case. So this swop may also not be entirely straight forward.

And while there is no doubt that the H260 is stronger, but I am fairly sure the H233B should be quite strong enough. How much torque does that motor produce?

[AndriesS]

The manual cars was fitted with the h260 while the auto's with h233, but this was not consistent across the Y61 range.

also see:
http://www.patrol4x4.com/forum/nissan-p ... -types-29/

[Kagiso II]

alex - gooi daai tyotta betteri weg en plak 4.8 patrol alles daar in daai Witblits [dan sal jy nie so sukkel op Rhino se ou bultjies nie ... tot die nikswerd ou Boezman het daar ge-kroozzzz :-)

ernstig: Kontak TOYSAN [pretoria wes] en kry die voor en agter diff van 'n 4,5 of 4,8 ... en terselfdertyd die HANDREM wat met daardie opset pas.

dink ek enou sommer hardop??

[Alex Roux]

Kagiso: As ek 'n 4.8 kon kry om in te sit sou ek nie twee keer gedink het daaror nie. Al is hy swaarder op brandstof. Maar daai go goed is so skaars soos hoendertande.

I had a very valuable chat with Gerrit Loubser this morning. My rear diff may be ok. Afterall 200,000km is a short life for a Patrol rear diff.
Since converting to Petrol the driving is more quiet. So I hear more noises going on.
Once of these noises is the humming at the back - but only when taking the foot off the pedal when going 120+ or else when going downhill.
Secondly it is not a worsening sound.
If I can live with the sound, it may be OK. R20,000 is a lot to pay if such a humming (heard sometimes) is annoying.
What I do need is a second opinion on the humming sound, from a trained ear. Peter Connan, you names was mentioned, so I will give you a PM, if you are prepared to listen to my driving?
This was potentially a very valuable chat with Gerrit, as I called him at the very gates of Mayfair gearboxes!

Kagiso: So van Rhino gepraat: Ek was net so bietjie verroes - net ge roll-back op die eerste bultjie. Ken ook nog nie my kar met die nuwe enjin nie. Daarna het ek nerens gesukkel nie. Maar hoe kan mens nou in elk geval sukkel met 'n Patrol?

[Alex Roux]

Its the original manual that came with the 3TD.
According to the site: http://www.patrol4x4.com/forum/nissan-p ... -types-29/
this was an H260 diff.

[Alex Roux]

Just to end this chapter...
Instead of replacing the crown wheel and pinion as suggested by the Gearbox company (roughly R20,000), I followed Peter Connan's advice and replaced the oil in the rear diff first.
So with some help I managed to replace this with the Nissan recommended 85W140 grade. The humming is almost completely gone. I still heard the humming faintly once this morning, but much better than before. So will keep an eye (ear) on it.
The previous owner must have replaced the oil with something inappropriate. The oil did not seem old (bright blue coloured?), but was much thinner.

Alex

[Peter Connan]

Alex I am very glad.