Thread: Portals

From what I've read some Mog portal axles are an easier fit than others. The 404 has drums and one end is misaligned but somebody said the 411 Mog portals where the right width. I'm not sure of this?
Price wise they are occasionally listed for 1500-2000+pounds on u.k sites and a uk mob does disc conversions for around £1000 but I've read a u.s manufacturer of ,brakes, AP I think, can make ones to suit far cheaper.

Whilst I dont mind my thread being hijacked I am also very keen to see what gets posted on this one. Sorry to brush you off previously I wasn't much in the mood to talk portals yesterday.

I have never seen the inside of the maxi-drives so I am not the right person to talk comparisons between the two. It seems the problems I am having, according to Wolfgang, are isolated. We are yet to pull apart my portals from the weekends sojourns however I can with a fair amount of confidence say that;

One of the output shafts (right rear) has snapped, I know this because the wheel is about to fall off and thats what happened last time.

A CV or front half shaft at the CV has snapped, I know this because its a pig to steer, I suspect this to be the right front only because thats where the weight was at the time (the left front was 8' off the ground).

I believe that either a wheel bearing assembly or the drive flange has gone in the left rear because of the pooling of oil on the inside of the rim, with an output shaft the oil pools on the outside of the rim.

Now whilst I have been told that these portals are a semi-floating design (by my mechanic and wolfgang) with my very limited experience I do question this somewhat by the fact that if an output shaft fails the wheel tends to fall off reasonably quickly, the first time within a few hundred metres but this time it lasted nearly 10km.

The output shafts also have a hole right through for the CTIS which I believe potentially weakens them somewhat.









The Tibus portals are designed as a bot on portal, they change a flange at the axle between the axle and the portal to differentiate between Mercedes, Landrover, Toyota and Jeep. Thats it and from there you can specify any rim of your choosing to go on the other end any they will send you the wheel stud pattern to suit. There are some differences in the braking systems to suit each model however these do not really affect the operation of the portal itself as the callipers bolt onto the outside.

Now what I know about the maxi-drives is that they used as much of the existing landrover parts as possible so the hub is the semifloating design on the end of every defender axle.

I am sure that people much more knowledgeable about portals than I will come and hopefully put it into lamens terms for us.

When I bought mine it was about keeping the geometry and a legal way to increase the track as well as being able to easily fit 35's on a puma, keeping the gearing and without all of the grief that goes with lifting them. Time has shown that for some reason it hasn't worked out so well for me, there is another new chapter on the horizon so stay tuned.

In the meantime thanks for starting this thread.

Just one thing Iain

Solid axle Land Rovers use Full Floating axles,NOT semi floating axles

Originally Posted by LowRanger

Just one thing Iain

Solid axle Land Rovers use Full Floating axles,NOT semi floating axles

Series 1 rear

Originally Posted by Ancient Mariner

Series 1 rear

Disco2 front and rear also but does the Maxidrive portals fit only the classic rover axles - which are full floaters.

The photos don't show enough to tell if the stub axle is semi-float or full float, but I am inclined to believe the call on semi-float, and that fits with the fact that the wheel is nearly falling off.

Maxi-drives are full float, as are Marks, Volvos are semi-float, but properly engineered with ~70mm diameter stub shaft. I haven't had anything to do with Mogs.

The arrangement of the gears in a Maxi-drive, or Marks, are similar. They have to be because the stub shaft needs to rotate in the same direction as the half shaft from the diff. Volvos don't have the idler gear, they use a reverse rotation crown wheel in the diff, so that the stub shaft rotates in the correct direction. IMHO the Volvo arrangement is better, for reasons that I don't need to go into.

Maxi-drive, Marks, and Volvo use cast iron, probably SG iron but I can't say for certain for the portal boxes. Those use aluminium

MAXI-drive, et al put the strong side of the portal case on the side where the loads are greater, where those have the weak cover on that side

Maxi-drive and Marks have respectable bracing to the portal box, those have poor bracing that is nearly worthless. Volvos don't require bracing their design is tremendously strong.

Getting back to the semi-float stub shaft now. The diameter and material came up following the previous failure, and appeared better than that used on Nissan Patrols with semi-floating axles, even larger than the axles for the large H260 (260mm diameter crown wheel and 37 spline axles), so on paper should be reasonable.

I couldn't tell from where I am, what was going on, but clearly something wasn't right. I suspect a lack of resilience coupled with stress raisers, and possibly not the best material choice.

The problem with that design using idler gears vs Volvos, is being forced to reduce sizes. The small gear limits the diameter of the stub axle. The stub axles should not have been semi-float

Germans are renowned for their technical design, but they don't always get it right. Some years ago I was gainfully employed for greater part of a year fixing design issues in a German designed rolling mill after the warranty period - so even their huge industrial companies are not infallible. By comparison I recall a Japanese rolling mill being commissioned and exceeding design capacity within a week, where the German mill always struggled to get close to design capacity and has since been sold off to an Indonesian company.

I had actually contacted Tibus to see if they were interested in making Portals for a D3. The thought of being able to run 35's on a D3 really intrigues me to say the least. Especially with the adjustable independent air suspension.

Anyway I'm now glad they said no in their German abrupt way after seeing the many drama's Chook has been having.

Originally Posted by LowRanger

Just one thing Iain

Solid axle Land Rovers use Full Floating axles,NOT semi floating axles

Yes Wayne your correct, I see you passed my attention test

I did mean full floating my brain was typing semi for everything. I will take some photos of the individual components this evening and see what the general consensus is.