Rover Diff Failures

[Jay]

have a Maxi 4.11 sitting around...Thinking to install it on the Rangie(83 LT 95 32" Simex). However the bevel pinion gears inside the rover diff are the weak point and its the center axle holding them that breaks usually.
When this breaks will it wreck the CR&P....Am I better off waiting till i have lockers in this truck which might never happen....

Jay

[LUCIFER]

have a Maxi 4.11 sitting around...Thinking to install it on the Rangie(83 LT 95 32" Simex). However the bevel pinion gears inside the rover diff are the weak point and its the center axle holding them that breaks usually.
When this breaks will it wreck the CR&P....Am I better off waiting till i have lockers in this truck which might never happen....

Jay

Hi.. generally the spider gear shaft is the weakest link and goes with a bang.Once it snaps it often punches a hole into the housing and the left over case hardned matrial with cause severe damage to the CR & P in most cases..

I would look into putting a locker and axles into it before destroying a good set of gears. you might bust it tomorrow or it might last a life time, but it comes down to your driving style.

cheers

[Suspension Stuff]

I reckon you should install it before you go out wheeling again. All the other bits that brake usually damage the crown wheel in the process in my limited experience.

Shane

[Jay]

have a Maxi 4.11 sitting around...Thinking to install it on the Rangie(83 LT 95 32" Simex). However the bevel pinion gears inside the rover diff are the weak point and its the center axle holding them that breaks usually.
When this breaks will it wreck the CR&P....Am I better off waiting till i have lockers in this truck which might never happen....

Jay

Hi.. generally the spider gear shaft is the weakest link and goes with a bang.Once it snaps it often punches a hole into the housing and the left over case hardned matrial with cause severe damage to the CR & P in most cases..

I would look into putting a locker and axles into it before destroying a good set of gears. you might bust it tomorrow or it might last a life time, but it comes down to your driving style.

cheers

Hi i busted the spider gear shaft in my disco when I was still on stock 3.54 diffs....
So i guess i will wait until i have enough cash for an ARB as any other lockers like Detroit is far inferior in my opinion

Has anyone fitted 4.7 Rover Diffs into a 3.5 Rover Carby engine with an LT 95 4 speed gearbox....

Jay

[Slunnie]

The 4.7's are supposed to be pretty weak. They just have small pinions due to the gearing. The OE ones are probably made from butter also.

[Jay]

The 4.7's are supposed to be pretty weak. They just have small pinions due to the gearing. The OE ones are probably made from butter also.

For moderate driving without lockers it should be ok I guess.

Has anyone ran the 4.7's on an LT 95 geabox and 33" will the driving be ok on highways

Thanks

[Snarba]

what about running S111 land rover diffs? they are 4.7 standard I believe. I'm running these in my rangey with 38's ( not locked ) and they are holding up ok. just stay gentle on the right foot

[walker]

I am assuming the Series 3 C&P does not bolt straight into a Rangie diff since I have not heard of anyone else using them. Is this right?

[ISUZUROVER]

I am assuming the Series 3 C&P does not bolt straight into a Rangie diff since I have not heard of anyone else using them. Is this right?

A complete series (4.7) diff centre will bolt straight into a Rangie housing and vice versa.

If you want to swap just the R&P's, you can fit a series 4.7 R&P into a Rangie casing/diff centre, but you need a spacer for the ring gear (maxi-drive and other places sell these). You need the spacer because the flange on a 3.54 centre is in a different location to the flange on a 4.7 centre. So obviously you cannot fit a 3.54 R&P into a series casing/centre.

The reason they are not run commonly is that they are not very strong (compared to a 3.54). 10 small pinion teeth and 47 crownwheel teeth. GBR in the US make a stronger version in a 4.75 ratio with 8 thicker pinion teeth and 38 crownwheel teeth.

[Jay]

Ben

I have in ind to throw in complete 4.7 diffs I have had them in junkyteard for years....
Issue I am concened about is getting very high RPM with say a 33 or 34"....But that carburetor engine is slow compared to the 3.9 injection that came out later on...

[walker]

Ok, Ben, I have heard the OME 4.7 is weak but how about the one out of the Salisbury diff they had on the long wheelbase.

I only ask because I have been trying to work out what to do for a while. I have a bomb of a Rangie which is only for offroad. I run 35's on it but have not been able to afford/justify the expense of the 4.11 (about$1700 fitted). Also if you break a 4.11 then it's big money again to replace it. I would go Toyo but I have already forked out money on maxidrive lockers & axels.

I would expect the series 3 C&P to be a lot cheaper.

PS. Sorry Jay I have pinched your thread.

[uninformed]

Ok, Ben, I have heard the OME 4.7 is weak but how about the one out of the Salisbury diff they had on the long wheelbase.

I only ask because I have been trying to work out what to do for a while. I have a bomb of a Rangie which is only for offroad. I run 35's on it but have not been able to afford/justify the expense of the 4.11 (about$1700 fitted). Also if you break a 4.11 then it's big money again to replace it. I would go Toyo but I have already forked out money on maxidrive lockers & axels.

I would expect the series 3 C&P to be a lot cheaper.

PS. Sorry Jay I have pinched your thread.

hey walker, yes the sals r&p is stronger, its hypoid not spiral bevel. but if you can have a look at a sals and a rover. "i don't think you'll fit all that steel in that little handbag"

cheers, Serg

[ISUZUROVER]

Ok, Ben, I have heard the OME 4.7 is weak but how about the one out of the Salisbury diff they had on the long wheelbase.
I would go Toyo but I have already forked out money on maxidrive lockers & axels.

The 4.7:1 salisbury is incredibly strong, but is a completely different animal to a rover diff. To give you and idea of just how different, the rover diff has an 8.25" crownwheel diameter, the Salisbury 9.75". A Maxi-Drive locker for a rover diff is completely different to a Maxi-Drive for a Salisbury diff.

[ISUZUROVER]

Ben

I have in ind to throw in complete 4.7 diffs I have had them in junkyteard for years....
Issue I am concened about is getting very high RPM with say a 33 or 34"....But that carburetor engine is slow compared to the 3.9 injection that came out later on...

Bobtail on here (don't know if he still posts) used to run series 4.7 diffs in a comp Rangie he built, with a carb 3.5, LT95, Twin MD lockers and procomp 35's. Don't know what high range ratio it ran, but it seemed to manage on the highway fine. He got a pretty good run out of the 4.7s, but he is a good driver. Even so, I think the guys he sold it to broke more CVs (stock RR) than diffs.

[Jay]

Ben

I have in ind to throw in complete 4.7 diffs I have had them in junkyteard for years....
Issue I am concened about is getting very high RPM with say a 33 or 34"....But that carburetor engine is slow compared to the 3.9 injection that came out later on...

Bobtail on here (don't know if he still posts) used to run series 4.7 diffs in a comp Rangie he built, with a carb 3.5, LT95, Twin MD lockers and procomp 35's. Don't know what high range ratio it ran, but it seemed to manage on the highway fine. He got a pretty good run out of the 4.7s, but he is a good driver. Even so, I think the guys he sold it to broke more CVs (stock RR) than diffs.

I think with 33 or 34" it might be too high...
I have the diffs so I am going to thrown them in and in case they are too high refit the 3.54 complete diffs

Jay

[Lao Tsu]

I ran 4.7's from a series in my old hybrid, with 35/12.50x16's (BFG MTs) and never broke one in three eyars of hard off roading. The old girl had three engines in that time ending up with a Supercharged 3.5. With 35's you will be just a snadge under geared so with 33's you will need an O/D to cruise easily on road.

KAM do HD pinions and mounting bolts for the 4.7 which is a damn site stronger than the stories allow - if you drive it right!

[Slunnie]

I think when I was working my diffs out, 33's equated to 4.11's and 35's to 4.3's.

[Jay]

I think when I was working my diffs out, 33's equated to 4.11's and 35's to 4.3's.

Agree slunnie when I did the math for my 35" for the disco I needed a 4.3 which you can only find in TOYs (my nect project).

In Lebanon it is very hilly so we have some uphill dirving. Some people run even 32" with the standard 4.7....

Jay