Thread for LT230 H/L/CDL Knob

[isuzurover]

The threaded insert that the knob presses onto on my '87 model LT230 has disintegrated. Anyone know what thread it is, because it is a bit hard to take off to take into the bolt shop!!!

[rovercare]

Prolly either UNF or Metric fine, my bets on UNF

1. Drive to bolt shop

2. ask for UNF nut similar size

3. Go from there

[Bush65]

The bush for the knob which was on the original Lt230 in 84 rangie does not have a thread.

The bush is a hard rubber, which pushes into the knob. When it is screwed onto the thread of the shaft, the rubber deforms to the thread and the pressure holds the bush tight in the knob.

From memory, when I made an extension to suit the body lift, I think the thread was M10 (may have been M10 fine).

[isuzurover]

The bush for the knob which was on the original Lt230 in 84 rangie does not have a thread.

The bush is a hard rubber, which pushes into the knob. When it is screwed onto the thread of the shaft, the rubber deforms to the thread and the pressure holds the bush tight in the knob.

From memory, when I made an extension to suit the body lift, I think the thread was M10 (may have been M10 fine).

Thanks John - I maybe didn't explain myself clearly. I wanted to know the thread of the shaft, as I want to get rid of the crappy rubber insert and get a nut with the right thread which I can press into the knob. M10 (coarse) looks about right.

[1103.9TDI]

A piece of standard vacuum hose, pushed into the knob, then threaded onto the stick, works a treat. Nothing like a nice tight fit!.

[lokka]

A piece of standard vacuum hose, pushed into the knob, then threaded onto the stick, works a treat. Nothing like a nice tight fit!.

G'day im with gerry i did the same thig to both my high / low selector and gear seloctor knobs with rubber hoseand has worked a treat the original bush is ruber and usualy melts ive seen a few that have done this and the rubber hose is a cheep n easy fix

cheers

chris

[JDNSW]

A piece of standard vacuum hose, pushed into the knob, then threaded onto the stick, works a treat. Nothing like a nice tight fit!.

Yes. Used this on my main gear lever.

[Bigbjorn]

From memory, when I made an extension to suit the body lift, I think the thread was M10 (may have been M10 fine).

There are at least four thread pitches in common use in 10mm. diameter, 0.75, 1.0(spark plug), 1,25, 1.5. I will measure and gauge one and post it here.

[isuzurover]

Thanks guys - maybe the vacuum hose is a good idea.

Brian - AFAIK there are only 2 ISO metric pitches - COARSE (standard) and FINE.

There are two kinds of ISO metric threads: coarse and fine.

The ISO metric thread profile and proportions are as follows:

Metric Thread Pitch and Tapping Sizes
Size Pitch (mm) Tapping Diameter (mm) Clearance Holes (mm)
Coarse Fine Coarse Fine Close Medium Coarse
M1.6 0.35 1.25 1.7 1.8 2.0
M2 0.4 1.6 2.2 2.4 2.6
M2.5 0.45 2.05 2.7 2.9 3.1
M3 0.5 2.5 3.2 3.4 3.6
M4 0.7 3.3 4.3 4.5 4.8
M5 0.8 4.2 5.3 5.5 5.8
M6 1.0 5.0 6.4 6.6 7.0
M8 1.25 1.0 6.8 7.0 8.4 9.0 10.0
M10 1.5 1.25 8.5 8.7 10.5 11.0 12.0

[Bigbjorn]

Thanks guys - maybe the vacuum hose is a good idea.

Brian - AFAIK there are only 2 ISO metric pitches - COARSE (standard) and FINE.

Taps and dies are my business. Do you want me to send you one of each as proof? C.O.D. Best prices in Oz. The MSDC catalogue also lists M10 x 0.5, I did say in common use. They also list 5 pitches in M8, 5 in M12, 5 in M14, 6 in M16, 6 in M18, 5 in M20.

The only legal standard is ISO which is what manufacturers call Metric coarse. Any others do not appear in the ISO Standard. Refer Sidders Guide to World Screw Threads, or Machinery's Handbook 27th. Edition.

There are the following Metric thread systems that I know of:- ISO, French Metric, French Automotive, Swiss Engineering, Swiss Horological, DIN, Swedish Inst. Marine Engineers. Fortunately they all use the same 60 degree thread profile. The differences are in the pitches listed in the different standards and the tolerances.

I stock taps and dies in the following systems:- BSW, BSF, BSB, BSC, BSCon, Admiralty Fine, UNC, UNF, UNEF, UNS, Metric, ISO r & c (BSP), NP, all spark plug sizes, and a number of "specials" selected by manufacturers for God knows what reason. I have supplied any number of unlisted "specials" over the years, including the coach head bolts on Ford T trembler coils, 5/16" x 30 used on axles of penny farthing bicycles, 7/16 x 16 used on Harley WLA & UL headbolts and nowhere else to my knowledge, uncommon sizes in 20, 24, 26tpi common pitch systems used on motorcycles.

I do not stock BA or ME because of limited demand and there are people who are doing them well. The sales volume of these systems doesn't justify another competitor.

All the above systems are in use today somewhere around the world. There are others such as Thoury, Seller's, USS "V" thread, Waltham, etc. that have passed into history and are now only used by repairers/restorers.

Got a fastener problem with your project? Call Brian.