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Re: Wishbone Rim Clearance

PostPosted: Tue May 24, 2022 3:06 pm
by types26/36
The washers are mentioned in the final drive section and shown fitted between the housing and wishbone.
At least one is shown in the early parts manual fitted between the w/b and housing although it could be viewed as fitted under the nut, they are also fitted on the outside.
I have always fitted them between the w/b and housing as I have seen where the bush cuts into the alloy housing if they were not fitted.
The topic has also been discussed previously on this thread.
viewtopic.php?t=30596&p=215201

Re: Wishbone Rim Clearance

PostPosted: Tue May 24, 2022 4:03 pm
by Hawksfield
Mike

I understand what your saying regarding the wear to the carrier but that means some movement of the steel centre of the bush that has not been tightened tight to it. its a pity Lotus design did not pick this up and give more space.

Brian

So much confusion with Lotus information the the part number is different to Rdent parts list and the wiki graphics does not specifically show where it fits.

Iam still learning after 49 years of Lotus ownership If and when the wishbone come off I will endeavour to improve the fit.
Thanks for yourcomments

Re: Wishbone Rim Clearance

PostPosted: Wed May 25, 2022 11:13 am
by Hawksfield
Brian

Thanks again for your comments and information.

Where did you get the article 14 Chassis section ?
The section you show on section R final drive Page 5 is not the same in my +2 Manual, no mention of replacing the wishbone in that section,
You are quoting a Elan 26 Manual.

This is consistent with Lotus confusion at least in documents.

Thanks

Re: Wishbone Rim Clearance

PostPosted: Wed May 25, 2022 12:39 pm
by lowflyer
Thanks Brian for the clarification that exploded view really helps.

I was wondering about this too, given that the early Elan Coupe I am restoring did not have thin washers between the wishbones and hub carrier, but there was a groove worn. These are the earlier Issue 16 castings.

hub.png and


I would also suggest, if possible, to drop the wishbone and measure the internal distance. This wishbone distance should be 5.68in or 144.27mm. Compare that to the overall width of the hub carriers. One of my hub carriers was 2.5mm wider than the other!

When metalastic bushes are fitted that pushes the bush outwards and reduces wheel clearance. In my case, fitting polybushes I decided to grind back the carrier to make both sides the same.

**Edit**
I just checked in the workshop. The "top hat" poly bushes have a far larger bearing surface than the metalastic bushes where only the end of the inner tube pressed against the hub carrier. My set up is as follows with washers for A and C. The top hat Polybush is shown as B and no washer.

hub2.png and


Washers shouldn't be needed with the 'top-hat' shaped poly bushes but please prove me wrong.

Re: Wishbone Rim Clearance

PostPosted: Wed May 25, 2022 4:14 pm
by types26/36
Hawksfield wrote:Where did you get the article 14 Chassis section ?
Thanks


John/Andy,
I got information from the early Master Parts List and the Early Manual for the Type 26 cars, the other text does come from the later manual also for the Type 26 in the Final Drive section.

Re: Wishbone Rim Clearance

PostPosted: Wed May 25, 2022 4:37 pm
by lowflyer
Thanks Brian for sharing the source information. I did study your book too when I was assembling the chassis just to see if there any vital details I'd missed!

I need to drop the wishbones anyway to install the diff so I'll investigate sliding some light duty washers next to the hub carrier.

The image you shared also helpfully confirms that I'm missing a pair of torque rod cupwashers!

Re: Wishbone Rim Clearance

PostPosted: Wed May 25, 2022 4:53 pm
by types26/36
lowflyer wrote:I need to drop the wishbones anyway to install the diff !


Andy, you only need to remove one wishbone (left side) to fit the diff as it goes in from that side.
Just in case you are not aware, if you are fitting a diff brace (as per Sprints) it must be fitted after the diff is in position (still loose) you will not get the diff in if it is attached first (if using a Lotus chassis) ……don’t know about Spyder chassis though.

Re: Wishbone Rim Clearance

PostPosted: Wed May 25, 2022 6:06 pm
by elanner
The wishbone-to-wheel clearance is tiny but the bolt head-to-wheel clearance is OK? I think that's unusual - isn't it the bolt head that usually fouls the wheel?

Is this with original steel wheels or modern alloy wheels (which provide less clearance)?

Does the thickness of the braising of the bush tube to the wishbone match those that have decent clearance?

Nick

Re: Wishbone Rim Clearance

PostPosted: Thu May 26, 2022 2:51 pm
by phil1800
BB7FA800-94C9-4FAC-A2FB-F65185036FD6.jpeg and
83969890-0DF1-40C1-A020-E039FD9816F5.jpeg and
2C23B914-4BBF-494C-B87A-9A073482C80D.jpeg and
We have a holiday here in Germany, so some time spend in the garage. First observation: The front bushing tube protrudes towards the bearing housing, the rear one towards the half- bolthead. There are washers under the bolt heads and at the bearing housing, but none under the nut. All washer are bow shaped and heavily worn. After flattening and cleaning, the bearing housing washers are 1,15 mm, the others are 1,75 mm.
To get more clearance at the front outer wishbone eye, I push the rear bushing tube towards the bearing housing, just like the front one. The bushing tubes are now 137,95 mm apart from each other, while the bearing housing measures 137,60 mm, which means I can‘t fit the slim washers. The wishbone outer eyes are 144,46 mm apart, which is 19/100 mm more than stated in the manual, but my measurements of the components on the car are not 100%.
Measuring the wishbone/ rim clearance, I can see the positive effect, with 1,78 mm at the front and 2,38 mm at the back.

As I think the inner slim washers should be fitted to preserve the aluminum housing, I will try to centralize the bushing tubes a bit, so that they protrude evenly to the front and the rear. Hopefully, this will still give me enough rim clearance.
Is this the right thing to do, as long as I run the old metalastik bushes ??? (I will order a poly kit asap).

Sorry for mixing up the pics again……..

Philipp

Re: Wishbone Rim Clearance

PostPosted: Thu May 26, 2022 5:35 pm
by snowyelan
A poly setup as shown above will rub the housing continuously during suspension movement unless a washer is sandwiched between the inner sleeve and housing. Do you have space for this?

Re: Wishbone Rim Clearance

PostPosted: Thu May 26, 2022 6:26 pm
by phil1800
Poly Bushes: I measured a 6,67 mm gap between wishbone and housing, i.e. 3,3 mm for each side. That should be OK.
What is the group’s recommendation when it comes poly bushes. I see different vendors and prices. What‘s the best option/ manufacturer and supplier?

Philipp

Re: Wishbone Rim Clearance

PostPosted: Thu May 26, 2022 6:47 pm
by snowyelan
Hi Philipp,

3.3 is probably enough for the top hat 'brim' but not enough for both washer and brim. Poly bushes work differently than the bonded rubber originals in that they slide around the inner sleeve to allow for movement. The rubber style don't, the rubber just deforms. My point is that the brim will be sliding against the alloy housing and will cause some wear.

Re: Wishbone Rim Clearance

PostPosted: Thu May 26, 2022 6:54 pm
by 661
phil1800 wrote:Poly Bushes: I measured a 6,67 mm gap between wishbone and housing, i.e. 3,3 mm for each side. That should be OK.
What is the group’s recommendation when it comes poly bushes. I see different vendors and prices. What‘s the best option/ manufacturer and supplier?

Philipp

I used polybushes everywhere on my road car, except the rear outer bearings, where I used these:
https://kelvedonlotus.co.uk/product/com ... r-a-frame/

Re: Wishbone Rim Clearance

PostPosted: Thu May 26, 2022 8:57 pm
by h20hamelan
May have missed it, which hubs are installed on the rear. I think the front hubs are more narrow, and the rear there are a few options.
Would it be easy to check space between wheel arch to rim?
Looking at it from a different approach?

https://www.tonythompsonracing.co.uk/parts/hubs/

Re: Wishbone Rim Clearance

PostPosted: Fri May 27, 2022 11:10 am
by Roland
Just a few things here raised for interest.

I have polybushed my rear wishbones and in doing this I decided to buy new rear wishbones, old ones were fine but I wanted a set with metaplastic bushes to refit if required ever. I found that dimensionally the remanufactured wishbones vary considerably from Lotus dimensions, I had to actually return a set to one company because they were too wide on the outer end to polybush. After actually getting dimensions of wishbones before buying for a second time I concluded that TTR rear wishbones seemed to be the closest to Lotus dimensions, so I bought these. Note the TTR wishbones have a small amount of material removed from the eye increasing the clearance between the wishbone eye and inside of the wheel rim. So I have clearance of around 4 mm each side.

I realise that few people may be replacing rear wishbones, however if you are be careful what you buy because many seem to deviate from Lotus dimensions.

Rgds

Roland