12 replies to this topic

[Mini 360]

I am looking to purchase new bolts for my gearbox rebuild from Titan classics.  Reason being its a show car and I want fasteners that won't tarnish with the car being in storage/exposed to moisture on the road.  

 

I have a spare gearbox but really don't want to be taking it apart just to see what bolts are on it so was wondering if there are any comprehensive lists of bolt sizes used on an A-pus engine and box?  I know most are 5/16 or 3/8 blah blah but need to know size, pitch, lengths and type of bolt/screw used before I spunk a whole heap of money on Titans epic range.

[RedRuby]

You could pm john from guessworks who is a member on here and rebuilds gearboxes so he will probably be your best bet.

[AlexMozza]

Somerford mini have a exploded diagram of all components on minis with what type of bolt should be used, size ect.

 

http://www.somerford...age=page&id=157

Edited by AlexMozza, 07 April 2017 - 06:00 PM.

[Swift_General]

Look online. Plenty of parts catalogues on various sites.

[AndyR]

I have a gearbox on my bench at the mo that i did the exact same with ARP bolts, i didnt make a list but will take 5 mins tomorrow to make one for you.

 

Andy

[nicklouse]

So what bolts are you wanting to replace with ones of a lesser quality?

Most ones that don't rust/tarnish are not up to the job.

[AndyR]

As promised

 

Gearbox to Block

(5 x) 1/4" UNF x 1.5”

(7 x) 1/4" UNF x 1”

(1 x) 1/4" UNF Nyloc Nut

 

Clutch Cover  / Wok

(8 x) 5/16” UNC x 0.75"

 

Clutch Housing to Block

Inner

(4 x) 5/16” UNC x 1.75”

(1 x) 5/16” UNF Nyloc Nut

(3 x) 5/16” UNF x 1.75”

 

Outer

(1 x) 5/16” UNC x  1.75"

(3 x) 5/16” UNC x 1.25"

(2 x) 5/16” UNF x 1”

(1 x) 5/16” UNF x 0.75"

 

Speedo Housing

(5 x) 5/16” UNC x 1.00”

(2 x) 5/16” UNC x 3.50”

(1 x) 5/16” UNC x 1.50”

(3 x) 1/4” UNC x 0.75”

 

 

Diff Housing

(2 x) 3/8” UNC x 4.00”

(2 x) 3/8” UNC x 2.50”

(3 x) 5/16” UNC x 2.75”

 

Output Shafts

(10 x) 5/16” UNC x 1.00”

 

Oil Pickup Pipe

(2 x) 1/4" UNF x 1.5” + Nyloc Nuts

 

I would suggest chasing all the threads with a bottom tap to ensure you get the bolt all the way in on blind holes as they can be filled with crud.  Or you may need to reduce the blind hole bolts by an 1/8".

 

As suggested, unless it is a pure show car and non driver i would be careful with using Ti bolts.  Also as Titanium is much more Noble than the cast Aluminium box you will experience anodic corrosion of the alloy.  If you absolutely have to use them then i would suggest using a good quality anti seize (and preferably not graphite based)

 

Andy

[nicklouse]

Not to mention Ti is nowhere the strength of the bolts required.

Edited by nicklouse, 09 April 2017 - 12:20 AM.

[tiger99]

Well said! A lot of people don't realise that Titanium is not as strong as high tensile steel on the basis of diameters being equal. It only wins when you compare by mass, and use larger bolts.

The only real hope for any bolts on the Mini is to have the standard 8.8 (actually "should" be Grade S) bolts plated and properly heat treated afterwards to reduce the otherwise very serious risk of hydrogen embrittlement. You can probably also plate 10.9 but it would be ill advised with 12.9. Doing this safely really requires the services of an aerospace or similar plating company, definitely not one that does decorative work, or a kit from the likes of Frost, and will be very expensive.

I hope you are not planning on using fancy bolts anywhere else on the car. In the steering and suspension they are real killers.

[Mini 360]

As promised

 

Gearbox to Block

(5 x) 1/4" UNF x 1.5”

(7 x) 1/4" UNF x 1”

(1 x) 1/4" UNF Nyloc Nut

 

Clutch Cover  / Wok

(8 x) 5/16” UNC x 0.75"

 

Clutch Housing to Block

Inner

(4 x) 5/16” UNC x 1.75”

(1 x) 5/16” UNF Nyloc Nut

(3 x) 5/16” UNF x 1.75”

 

Outer

(1 x) 5/16” UNC x  1.75"

(3 x) 5/16” UNC x 1.25"

(2 x) 5/16” UNF x 1”

(1 x) 5/16” UNF x 0.75"

 

Speedo Housing

(5 x) 5/16” UNC x 1.00”

(2 x) 5/16” UNC x 3.50”

(1 x) 5/16” UNC x 1.50”

(3 x) 1/4” UNC x 0.75”

 

 

Diff Housing

(2 x) 3/8” UNC x 4.00”

(2 x) 3/8” UNC x 2.50”

(3 x) 5/16” UNC x 2.75”

 

Output Shafts

(10 x) 5/16” UNC x 1.00”

 

Oil Pickup Pipe

(2 x) 1/4" UNF x 1.5” + Nyloc Nuts

 

I would suggest chasing all the threads with a bottom tap to ensure you get the bolt all the way in on blind holes as they can be filled with crud.  Or you may need to reduce the blind hole bolts by an 1/8".

 

As suggested, unless it is a pure show car and non driver i would be careful with using Ti bolts.  Also as Titanium is much more Noble than the cast Aluminium box you will experience anodic corrosion of the alloy.  If you absolutely have to use them then i would suggest using a good quality anti seize (and preferably not graphite based)

 

Andy

Many thanks!  Haven't bought anything yet so still in research stages.  Just want a list so I can source things and price them up.

[Spider]

As promised

 

Gearbox to Block

(5 x) 1/4" UNF x 1.5”

(7 x) 1/4" UNF x 1”

(1 x) 1/4" UNF Nyloc Nut

 

Clutch Cover  / Wok

(8 x) 5/16” UNC x 0.75"

 

Clutch Housing to Block

Inner

(4 x) 5/16” UNC x 1.75”

(1 x) 5/16” UNF Nyloc Nut

(3 x) 5/16” UNF x 1.75”

 

Outer

(1 x) 5/16” UNC x  1.75"

(3 x) 5/16” UNC x 1.25"

(2 x) 5/16” UNF x 1”

(1 x) 5/16” UNF x 0.75"

 

Speedo Housing

(5 x) 5/16” UNC x 1.00”

(2 x) 5/16” UNC x 3.50”

(1 x) 5/16” UNC x 1.50”

(3 x) 1/4” UNC x 0.75”

 

 

Diff Housing

(2 x) 3/8” UNC x 4.00”

(2 x) 3/8” UNC x 2.50”

(3 x) 5/16” UNC x 2.75”

 

Output Shafts

(10 x) 5/16” UNC x 1.00”

 

Oil Pickup Pipe

(2 x) 1/4" UNF x 1.5” + Nyloc Nuts

 

I would suggest chasing all the threads with a bottom tap to ensure you get the bolt all the way in on blind holes as they can be filled with crud.  Or you may need to reduce the blind hole bolts by an 1/8".

 

As suggested, unless it is a pure show car and non driver i would be careful with using Ti bolts.  Also as Titanium is much more Noble than the cast Aluminium box you will experience anodic corrosion of the alloy.  If you absolutely have to use them then i would suggest using a good quality anti seize (and preferably not graphite based)

 

Andy

 

Great list Andy, thanks for posting up.

 

I think the 3 (or 4 if an earlier gearbox) bolts for the Main Bearing Retainer maybe missing from this list though ?

 

These are 5/16" UNC x 1.0" Grade 5 Set Screw.

 

The others were Grade 3.

 

Those 1-1/4" or shorter in length were Set Screws, the other were Bolts.

[GraemeC]

A great list Andy.  I'd have to question a couple of fixings though:

 

- Where is the nyloc nut under 'Clutch Housing to Block Inner'?  From memory these are all set screws into threaded holes.

- I've always known the 3x UNF set screws for Clutch Housing to Block 'Inner' to be the same length (1")

 

If the intention is for the A+ bolts to look 100% original then they should be the flanged type with a head size smaller than normal for the thread size (ie a 5/16" UNC set screw would have a 7/16"AF hex head.

Many of the flanged bolts are still available from MiniSpares (DAM7755, DAM7756, DAM7758, DAM7759, DAM7761)

 

(For A series boxes many of these bolts and set screws were studs and nuts)

[AndyR]

I must admit that this may not be 100% as original, as i have compiled this list from the engine/box that i am rebuilding (compared with what was removed), that was rebuilt by another well known mini company.  So things may be ever so slightly different.  Most were checked for depth with a vernier caliper and slightly adjusted if i thought that the bolt didnt penetrate enough.  Thats why the 1.75* inner bolts may be longer, and there may be a stud here and there that may have been a set screw or vice versa.  I know many prefer studs and bolts instead of the set screws on the diff housing for example.

 

Mokespider may be correct that i have left off the main bearing retainer fixings, i will take a look this evening.

 

So please take the list with a pinch of salt and please feel free to ammend if i have made mistakes.

 

Andy