4.75 & 4.11 Rover Gears

[krazz1e]

Ok asking for advice now suckers

Any you guys run 4.75 before you upgraded to bigger and better things? Would you agree 10x41 4.11 are stronger than stock 3.54 13x46?

some options out there:
GBR 4.11 10x41
GBR 4.75 8x38
KAM 4.11 ?
KAM 4.75 ?
Stock Series 4.7 10x47
Stock 3.54 13x46

according to KAM's website the 4.75 is 50% stronger than a stock gear set. How can that be true?

GBR 8x38 claims that there is less teeth but they are thicker allowing for greater strength. how can less teeth be stronger than series 4.7 10x47. In real life this does seem to be the case.

Look, don't want to hear go toy, go sals, go dana blah blah. People who ran these only please. Thank you amigo's

[Buckon37s]

go toy, go sals, go dana

[Agrover]

Thicker teeth allow for a thicker more ductile core. but I would assume this would be offset a little by having less actual teeth in mesh. I ran English Ford Transit diffs in my Rover at one time, and their 5.6 :1ring and pinions were actually stronger than their 4.625:1 due to less but thicker teeth.
I would like to see some company design a ring and pinion that continues the length of the ring gear teeth all the way to the circumference ofthe carrier as Toyota did on their later Landcruiser diffs
Bill.

[nunoeumiranda]

I used the series and broke 2 in a half
I bought the KAM 4,75 and until now nothing to say.. running very well with my MAxxis 35".... never broke

But definitely GO TOY

[Greg Davis]

I ran the 4.75's in my DII and lost some teeth off the ring gear on my first trip to Moab. From what we could tell, the pinion deflected enough to take off the ends of a few of the ring gear teeth. Ended my trip right there since GBR was out of stock at the time.

[evilfij]

"Would you agree 10x41 4.11 are stronger than stock 3.54 13x46?"

NO!!!!!

Lower numerically is stronger. 4.11 blow up as do, especially the 4.75s. someone posted up about pinning the diffs, short of that you will break them.

Salisbury rear, toy front or Eaton Rear/D60 front.

[aloharover]

Originally Posted by evilfij

Salisbury rear, toy front or Eaton Rear/D60 front.

Call dynatrac and just have them make D60 f&r for you. Change to a more common (ie. cheeper to get rims) bolt pattern.

[evilfij]

Salisbury rear, toy conversion front keeps the rover bolt pattern.

Eaton rear, D60 front is 8 lug.

You have have gold plated daytona 144 spoke 20s for the cost of a pair of dynatrac 60s as opposed to $1500 for either of the above combos.

[aloharover]

Originally Posted by evilfij

Salisbury rear, toy conversion front keeps the rover bolt pattern.

Eaton rear, D60 front is 8 lug.

You have have gold plated daytona 144 spoke 20s for the cost of a pair of dynatrac 60s as opposed to $1500 for either of the above combos.

So you are saying you can find a Salisbury here in the US and do the toy conversion for 1500$?

[evilfij]

I am cheap. Maybe you end up at around 2k-2500 after lockers.

My salisbury was $250 or so. ECR blows them out every year at that price or less for the drum take offs (last year it was $150). $325 for the Detroit and $400 for shafts.

Pick and pull the toy diff for $50.

What does keith get for the toy axles? I know the rover ones he sells are $660.

Ron

[aloharover]

Originally Posted by evilfij

My salisbury was $250 or so. ECR blows them out every year at that price or less for the drum take offs (last year it was $150). $325 for the Detroit and $400 for shafts.

What are they swapping out the Salisbury for?
I had never seen a RTR complete drum to drum rear go for less the 700$ before.

[evilfij]

ECR swaps out all the drum brake 110 rears for complete 110 salisbury disc axles. They sold two or three last year but I was too busy to drive up (they also had a take off 110 SW tub which is what I really wanted, but it sold before I had a chance to get up there).

I bought mine out of Ohio for $250 or $300 IIRC four years ago, and it had the sway bar mounts on it.

[krazz1e]

$300 for a sals? sign me up.

ok some good info folks.

So shifting gears now, Toy Front gives 30 spline and more options on gearing. I've seen a toy R&P and they don't seem much beefier, so why are they stronger?

[grnrvrs]

It's the fundamental design of the diff!

toy=hypoid: pinion intersects the ring off set towards the top or bottom of the ring
rover=shit i.e. spiral bevel: pinion intersects the ring at the center

Yeah, there are some stout spiral bevel 3rds i.e. ENVs, but the larger larger tooth engagement area for a hypoid style diff is stronger than rover shit, given the same ring diameter, R&P ratio...

[ashtrans]

Originally Posted by krazz1e

Ok asking for advice now suckers

Any you guys run 4.75 before you upgraded to bigger and better things? Would you agree 10x41 4.11 are stronger than stock 3.54 13x46?

some options out there:
GBR 4.11 10x41
GBR 4.75 8x38
KAM 4.11 ?
KAM 4.75 ?
Stock Series 4.7 10x47
Stock 3.54 13x46

according to KAM's website the 4.75 is 50% stronger than a stock gear set. How can that be true?

GBR 8x38 claims that there is less teeth but they are thicker allowing for greater strength. how can less teeth be stronger than series 4.7 10x47. In real life this does seem to be the case.

Look, don't want to hear go toy, go sals, go dana blah blah. People who ran these only please. Thank you amigo's

Hi,

we make and sell a heck of a lot of 4.11 R & P gears, ours use a 9/37 tooth count and we have very few problems with them, I have seen a couple of failures but usually only when the pinion bearings collapse or the driver owns up to jumping the front axle 5 foot in the air,

as a rule the lower the ratio the weaker the R & P gear assuming all other things are equal, as the ratio gets lower the pinion gets smaller diameter, so you are transmitting the same load through less teeth,

To answer your original question, despite the above theory I don't think there is a great deal of difference between the 3.54 and the 4.11, I have seen more broken 3.54's but this may be because :

1) there are more out there

2) often they fail because they are on the stock 2 pin diff centre that just flexes and lets the R & P get out of mesh,

although some people like the 4.75 ratio, I am not a great fan of them because of a few reasons :

the pinion diameter is too small and asking for trouble,

for most people they are too low and not ideal on the road (I guess this depends on tyre size),

very slow seller, the last batch of 50 we made too 2 years to sell, we sell over 300 4.11's a year,

[krazz1e]

so i think GBR gears are KAM gears.

nevertheless, I may be forced to go something else due to the lack of options and strength here.

I have a set of 4.75 special reverse cut gears for the front, I just need to find something strong for the rear... doesn't look like that will happen. Does anyone have some 4.75's laying around from swaps? Not thrilled to spend $500 for GBR when I know they will break.

[Buckon37s]

Originally Posted by krazz1e

so i think GBR gears are KAM gears.

nevertheless, I may be forced to go something else due to the lack of options and strength here.

I have a set of 4.75 special reverse cut gears for the front, I just need to find something strong for the rear... doesn't look like that will happen. Does anyone have some 4.75's laying around from swaps? Not thrilled to spend $500 for GBR when I know they will break.

Don't worry, your front will break too.

[revor]

Actually Yousef ran 4.75 GBR gears up front for a couple of years in his 90... He broke a lot of stuf but not those gears...
I'm not sure about the difference in ratio diff but what about 4.88 toy in the rear and 4.7 up front? it's only about 2.5%... I've never actually thought about it much..

[western110]

You guys all need to get 2.5na diesels in your rovers... you'll never brake anything that way

[mightymg1]

Originally Posted by ashtrans

Hi,

we make and sell a heck of a lot of 4.11 R & P gears, ours use a 9/37 tooth count and we have very few problems with them, I have seen a couple of failures but usually only when the pinion bearings collapse or the driver owns up to jumping the front axle 5 foot in the air,

as a rule the lower the ratio the weaker the R & P gear assuming all other things are equal, as the ratio gets lower the pinion gets smaller diameter, so you are transmitting the same load through less teeth,

To answer your original question, despite the above theory I don't think there is a great deal of difference between the 3.54 and the 4.11, I have seen more broken 3.54's but this may be because :

1) there are more out there

2) often they fail because they are on the stock 2 pin diff centre that just flexes and lets the R & P get out of mesh,

although some people like the 4.75 ratio, I am not a great fan of them because of a few reasons :

the pinion diameter is too small and asking for trouble,

for most people they are too low and not ideal on the road (I guess this depends on tyre size),

very slow seller, the last batch of 50 we made too 2 years to sell, we sell over 300 4.11's a year,

are yours reverse cut?

[krazz1e]

Originally Posted by revor

Actually Yousef ran 4.75 GBR gears up front for a couple of years in his 90... He broke a lot of stuf but not those gears...
I'm not sure about the difference in ratio diff but what about 4.88 toy in the rear and 4.7 up front? it's only about 2.5%... I've never actually thought about it much..

hmm perhaps, i'll look into this. but then again, the toy gears aren't that much beefier than rovers, though there are much more options and they are cheaper.

[krazz1e]

Originally Posted by mightymg1

are yours reverse cut?

no, ashcrofts are not.

Which brings me to my next question, how much stronger does the reverse cut make it?

I am 90% sure KAM & GBR are reverse cut (or were at one point).

[ISUZUROVER]

Originally Posted by krazz1e

no, ashcrofts are not.

Which brings me to my next question, how much stronger does the reverse cut make it?

I am 90% sure KAM & GBR are reverse cut (or were at one point).

Reverse cut gears should be used on the front only AFAIK - means they will be as strong as a rear when driving forwards. There is another option for a 4.7:1 diff - still a 10/47 ratio, but a very strong coiller only version made for the front diff of the Australian Army perentie 6x6s - it costs about $900 for one ring and pinion though (and yes it is reverse cut).

[Junkyddog11]

Originally Posted by western110

You guys all need to get 2.5na diesels in your rovers... you'll never brake anything that way

hmmmn...the only thing I can't break with the 2.5na is the fawkin' speed limit......

[PTSchram]

Originally Posted by Junkyddog11

hmmmn...the only thing I can't break with the 2.5na is the fawkin' speed limit......

LOL, the only thing I seem to break with my Rover is shock absorbers (and tires)