Diaries of the Noob Mechanic: Fuzzydunlop's '85 MR2

[FuzzyDunlop]

If you haven't yet, try posting on MR2OC first and see if we can figure out exactly what that hole is for.

http://www.mr2oc.com/showthread.php?t=423947

Thanks Jlee. I just thought about doing that right after I posted my new reply. \
I posted there and had my answer within 10 minutes! haha. Great source!

Its supposed to be a 24mm Drain Bolt with a copper crush washer. I can buy a new over sized self tapping one at my local auto parts store. According to the guys at MR2OC I can use the self tapping bolt and not worry about a few aluminum shavings getting inside - as long as its not an excessive amount it wont cause damage. Its healthier for the transmission to have a few aluminum shavings in it than a gaping hole! haha!

Why would you need Teflon tape?

Ummm. i guess my thought was that it might help prevent some oil leaking.
Maybe. I dunno.

 

[Eli]

LOL..

We don't just want to be patching holes with random things. Need to figure out what it is first.

Can you see it on a parts breakdown? Does anything go in it?

Edit: Oops, should have read more closely.

Wow, that hole used to have threads? What the hell happened? lol.. It's almost like someone drilled it out to tap it oversize, and didn't complete the job or something.

You were driving it around like this? lol

 

[jlee]

New posts at MR2OC:

The BGB for the C52 transmission shows this as the retaining bolt for the reverse idler gear shaft. It is not obvious whether the threads are supposed to be in the casing or in the shaft itself, but the assembly directions show an orientation for the shaft, and this suggests that the threads are in the shaft. If that is the case, then once the shaft had rotated you would no longer be able to find the threads. It is also not obvious whether the reverse gear can come loose if this bolt is missing. It is possible that the shaft is retained by the casing, and that you can get away with just plugging the leak.

On my E-58, the shaft is threaded. Forgot about this. You'll need an 8mm bolt if you're lucky enough for it to line up. Does the car go in reverse? Make horrible sounds?

 

[Eli]

Hmm. Interesting.

 

[FuzzyDunlop]

BIG UPDATE!

I borrowed my brothers tap and die set and fixed the transmission hole.

I used a M10-1.5 ---which means a 10mm diameter bolt with 1.5 threads per mm.

Jacked up the car

and started threading it in. I would make about 1/2 turn, then backed it out 1/4 turn, then make another 1/2 and back out... etc etc. until it was in deep enough. This insured that I was making a good clean cut and would pull out some shavings as well. While I was cutting some oil was still coming out, so that also pulled alot of the shavings out with it.

After I pulled out the cutter the tranny dripped like crazy - which is good because it probably pulled out most the aluminum shavings!

Then I took a bolt and ran a nut onto it and cut it down to the length I needed. Then I filed the edge slightly and pulled the nut off.

Then I put a copper crush washer on it, and screwed it into the tranny. Fit like a charm. No more oil leak! No more hole!! Heres a pic after I chipped all the old JB weld off and polished the area with brass brush.

On the down side... my distributor is STILL leaking - even after I rebuilt it...

After all that was done, my mechanic friend came over looked over the MR2. He picked at it, asked a few questions, and told me, "yup, just put the headlights on, and Ill write up a safety report tomorrow."
Today I picked up the saftey papers, sent them over to my insurance company, bingo bango bongo - its road worthy AND insured! yeaya!

Heres a pic of it with the new rims and minus headlamps.

Next step - maybe a different muffler, and body work.

 

[JCH13]

Very nice fix, and good tapping technique.

 

[Howard]

BIG UPDATE!
I used a M10-1.5 ---which means a 10mm diameter bolt with 1.5 threads per mm.

1.5mm pitch, not 1.5 threads per mm.

 

[JCH13]

1.5mm pitch, not 1.5 threads per mm.

i.e. one turn drives the fastener in 1.5mm

 

[FuzzyDunlop]

i.e. one turn drives the fastener in 1.5mm

ICIC, I was taking a guess at what exactly it meant. Forgot to put the question mark at the end of that statement! ahah.

 

[jlee]

Congratulations dude - you're getting there

 

[Howard]

i.e. one turn drives the fastener in 1.5mm

But what about double-start or triple-start threads?1?! Huh? HUH!?!??

 

[5150MyU]

Anyone?

 

[5150MyU]

All right -it is threads per mm-- as in 1.5 or 1.25<talking metric here.

 

[5150MyU]

Not saying your wrong -but your not right either.

 

[Eli]

Hmm.. I'm a little nervous about that fix.. I mean...why not just replace what is supposed to go there? lol

 

[Howard]

All right -it is threads per mm-- as in 1.5 or 1.25<talking metric here.

??

 

[JCH13]

But what about double-start or triple-start threads?1?! Huh? HUH!?!??

With multi-start threads you would still advance the pitch*number of starts (i.e. the lead). I was just trying to describe exactly what "pitch" is.

All right -it is threads per mm-- as in 1.5 or 1.25<talking metric here.

Not saying your wrong -but your not right either.

Then riddle me this batman: why do metric coarse threads have a LARGER pitch than fine metric threads?

See this.

In English fasteners, like 1/4-20, the 20 isn't the thread pitch, it is the number of threads per inch, which is 1/pitch. In metric fasteners the pitch is listed explicitly, in mm.

If you still don't believe me I can look it up in Machine Elements in Mechanical Design and Machinery's Handbook that I have sitting next to me at my desk.

 

[DivideBYZero]

Lawyered.

 

[mvbighead]

Gotta say dude, nice work. Reading this thread has me wanting to buy a fixer upper of some sort just to see if I can do it.

My current cars are both daily drivers though, so doing the kind of stuff you're doing isn't possible. Oh, when I move to a bigger house with an extra garage space...

 

[Howard]

With multi-start threads you would still advance the pitch*number of starts (i.e. the lead). I was just trying to describe exactly what "pitch" is.

But you were describing lead, hence my question.

 

[JCH13]

But you were describing lead, hence my question.

I assumed only 1 start, but I should have stated that assumption :hmm: :awe:

 

[Howard]

Lawyered.

stop doin that

 

[5150MyU]

Sorry I expained it wrong, I was drinking.
It is the distance from thread tip to thread tip.

 

[FuzzyDunlop]

ok. wow.

B is showing what I originally thought was 1mm. This is wrong.
After measuring with a regular clear plastic ruler I can clearly see that what A is showing is 1.5mm. So there is 1.5mm between threads (AKA Pitch). After reading JCH13's wikipedia article I learned much more about bolts and thread counting then I think I really need to know. lol.

Also, to say one complete turn would mean going from point RED to point BLUE, and would therefore drive the bolt 1.5mm in.
ok. Clear as mud.

 

[Howard]

Also, to say one complete turn would mean going from point RED to point BLUE, and would therefore drive the bolt 1.5mm in.
ok. Clear as mud.

only because it's a single-start tap