Front bearing adjustment

#1
Hi, I'm in the process of running-in my SPF MKII, with only 330 miles on the clock so far. I've noticed a sensation of "looseness" from the front of the car, and some new mechanical noises in time with wheel rotation, particularly on applying steering lock at low speed. On axle stands, there is considerable play in both front wheels on rocking at the 6 and 12 o'clock positions so I'm thinking the front bearings need adjusting.

Now, I'm keen to learn, but my enthusiasm exceeds my knowledge and experience when it comes to things mechanical! I have built and maintain a Caterham, and front tapered bearing adjustment involves removing the brake caliper and adjusting a castellated nut, being careful not to apply too much preload - I am fine with this. However the GT40 setup seems rather different!

Are there any "noddy" guides to doing this on the GT40 or similar cars? I've read all the threads on the rear bearing adjustment (this is definitely beyond me), in which there have been comments that front bearing adjustment is "straightforward", so I'd like to have a go if at all feasible, otherwise i will take it to a local mechanic.

One (or 2) more thing(s) - I've obviously seen all the comments about the bearing adjustment tool, and the tools for pulling the rear bearings from Olthoff. Is the bearing adjustment tool a pre-requisite for adjusting the front bearings, and thinking ahead to when I will get the rear bearings checked later in the year by the mechanic - will they need the specific GT40 rear bearing tools or is it likely they will manage without? The mechanic I have in mind is a Porsche specialist, but has a great deal of experience in 60s and 70s racing cars, including ground up rebuilds of Porsche 917s, and has done some work on an original GT40 (though some time ago)?

Thanks for any advice!

Chris
 
#4
Walt, I believe it is a non-tapered bearing. I believe the necessity for frequent adjustment is the price we pay for authenticity! There are numerous threads on this site about the rear bearings, a frequent comment is that the bearings don't have proper dust seals.

Jason, PM received, I'll respond in full later!
 
#5
There are numerous threads on this site about the rear bearings, a frequent comment is that the bearings don't have proper dust seals.

Jason, PM received, I'll respond in full later!
They do have seals, they are the SKF "Nilos" seals, a type many are not familiar with as they are not commonly used on road cars. www.skf.com/binary/30-228382/950-710-Nilos_08.pdf

Yes, the bearings can need adjustment more frequently than the common tapered type. As I tell customers " The great thing about the GT40 is it has all of the features of the original, the bad thing is it has all of features of the original"!
 
#6
Adjusting the front bearings is easy. Unfasten the 2 button head allen screws, remove the slotted lock plate and tighten the adjuster ring. You probably can tighten the adjuster ring without the Olthoff tool, but it does help. No need for the Olthoff axle pullers on the front bearings.
 
#9
Are we talking from the inner aspect of the upright? - can't see anything to fit with the description above looking at the outer aspect of the upright/hub. Excuse me if this is blindingly obvious! - I did say may enthusiasm outweighs my knowledge (and maybe my common sense) - the Caterham bearings are accessed from the outer aspect on the stub axle.

Just one more thing to add, I don't have the standard wilwood brakes, I have Wortec 6 pot calipers and discs, not sure if this would make any difference ( as per photo which is hopefully attached to this post!)

Chris
 

Attachments

#10
Sorry, was not clear.

Inside. The retaining ring is held on with a couple of Allen heads. You could do it with wheel on so the "remove" wheel is for ease of access, not because the adjuster is blocked by the wheel. Your calipers and discs make no difference.
 

Dave Hood

Member
Lifetime Supporter
#13
The bearings are one part on the Superformance cars that I wish they would have modernized, knowing that most of these cars are going to be driven on roads. I've had Holman Moody and Paul Whitlock machine and install crush sleeves to keep the bearings in place on my car. That has helped a great deal. Unfortunately those can't be massed produced since the measurements on each car are slightly different.
 
#14
Thanks for all your help, both front bearings were quite loose so I have adequately tightened them. I did also find that the left front top ball joint bolt was loose - I'd therefore like to do a general nut and bolt check - does anyone have a "workshop manual" or similar with a list of torque values for the major factory fixings eg suspension components etc?


Chris
 
#15
Hi Chris,

Just seen your post about bearings..

Superformance has undersized front and rear bearings so you'll have to replace or adjust them frequently.

There's no problem for US roads but as you know on European roads with many curves and sometimes bumps/holes, bearings suffer on GT40.

From my side I've upgraded front / rear bearing size (diameter and thickness) and since modification I have no problems !!!

No need too for a special tool to remove rear bearing. I'm sure your mechanic has a press that would be perfect to remove/replace/reinstall old/new bearings.

ROBY427
 
#20
That's it Markus / Rick thanks for your replies.

8000 miles since modifications and all is still ok.

Just for a remind (but many of you already know that) Timken bearings must have a minimum wear (mustn't be tighten with no wear). From my side to adjust them i've tighten them (no wear) and went counterclockwise 1/2 turn the big nut to get correct wear.

Roby427
 
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