bolt size for drive shaft flange bolts

[peclarkjr@msn.com]

Hello All,
I have an issue with a couple bolts. I have a 1991 Ford Ranger 4x4, 4.0L.
I notice a bolt missing and another bolt half way out on my drive shaft flange that bolts close to the transfer case. I just bought this truck this month.

I removed the one bolt half way out and took it to the parts store and we checked the thread size. They say its 1/2 13 which I witnessed they threaded it all the way through the test threads for 1/2 13 and it doesn't fit 12m 1.75. But everywhere I try to shop for these bolts sells them as 12m 1.75. They have the small 12pt head.

Any other Ranger owners have the older models that can verify the correct size ? Is it 12m 1.75 metric or 1/2 13 standard? I don't want to strip any threads.



Thank you

 

[adsm08]

1/2 is bigger than 12mm, 1/2 is about 13mm. I have never checked the threads, but I would think the 12x1.75 is more likely to be correct for two reasons.

1) The same bolt is still in use for drive shaft flanges.

2) As early as the 80s Ford was using metric threads. I have yet to find an ASE threaded hole on my truck, after 15 years of taking it apart and putting it back together.


I can try to find a bolt to check in the morning though. I'm pretty sure I have a few.

 

[jeremysdad]

Rusted metric 12x1.75 will thread perfectly though a 1/2x13...and vice-versa.

Just don't torque it down.

Metric is the way to go.

 

[jeremysdad]

Hello All,
I have an issue with a couple bolts. I have a 1991 Ford Ranger 4x4, 4.0L.
I notice a bolt missing and another bolt half way out on my drive shaft flange that bolts close to the transfer case. I just bought this truck this month.

I removed the one bolt half way out and took it to the parts store and we checked the thread size. They say its 1/2 13 which I witnessed they threaded it all the way through the test threads for 1/2 13 and it doesn't fit 12m 1.75. But everywhere I try to shop for these bolts sells them as 12m 1.75. They have the small 12pt head.

Any other Ranger owners have the older models that can verify the correct size ? Is it 12m 1.75 metric or 1/2 13 standard? I don't want to strip any threads.



Thank you

Also, 12 point heads are sooooo few and far between in the automotive world these days for SAE threads.

I would err to the side of google being your friend, or else your flange needs a new flange.

 

[peclarkjr@msn.com]

Thank you all for the help. I went ahead and ordered 12m 1.75 12 pt bolts for the flange. Should be here in a couple days and I'll have this fixed. Non of the car parts store had them in stock.

 

[Mark_88]

I hope they work for you...and you really should torque them down or tighten them and use locktite or similar...I've never had one come off in 16 years of Ranger driving...

If it turns out they are not right...I found a chart that has all ford bolts, screws and fasteners listed with their size, thread type, and length...all you need is the part number...and you can find that, usually, in the on-line manual...

I posted this information in the Submit info for Tech Articles section if you need it...

http://www.therangerstation.com/forums/showthread.php?t=165466

 

[jeremysdad]

I hope they work for you...and you really should torque them down or tighten them and use locktite or similar...I've never had one come off in 16 years of Ranger driving...

If it turns out they are not right...I found a chart that has all ford bolts, screws and fasteners listed with their size, thread type, and length...all you need is the part number...and you can find that, usually, in the on-line manual...

I posted this information in the Submit info for Tech Articles section if you need it...

http://www.therangerstation.com/forums/showthread.php?t=165466

FFor clarity, I meant not to torque mismatched-but-fit-cause-rusty sae/metric mix. Not the actual proper bolts. lol

 

[Mark_88]

FFor clarity, I meant not to torque mismatched-but-fit-cause-rusty sae/metric mix. Not the actual proper bolts. lol


As long as the thread and length are the same they should work...can't remember if the head of the bolt could be restricted by the way the coupler is moulded...but the heads are fairly small on the OEM bolts...

Last time I took one off was on the side of the road after the U-joint disintegrated so my memory is a bit faded...

 

[Andy D]

I think the only SAE threads on a Ranger are the lugnuts. Thanks fore reminding me to fix the CSB on the drive shaft. When I had it out I re-packed the bearing. Good for another 20 yrs. Only trouble is the bearing has come loose of the rubber support . I had great luck with the CSB in my 528e by wrapping it with a layer of doubled up taken off timing belt. It is only one of the 2 cars' commonalities.

 

[peclarkjr@msn.com]

Thanks a lot everyone. It was 12m 1.75. The bolts came via amazon. I just bought this truck last month. I drove it home four hours and it doesn't leak a drop of oil. I really like that 4.0 motor. I did notice drive line vibration so when I got home I checked and that's when I noticed 1 bolt missing and another half way out of the drive shaft flange going to the transfer case. The guy I bought it from did say the transmission was replaced so I'm thinking they didn't torque it down right.

I still couldn't get that 12m 1.75 to go in at first. Then I figured well maybe its been out a while and the threads are corroded so I used the same size TAP and ran it through. The bolt fit and they are all torqued correctly now with thread locker. After completing that I noticed 2 transmission mount bolts missing. One that goes up into the tranny and another that goes down through the tranny mount into the crossmember. I also replaced those and torqued.... it almost drives like a car now...lol.

I really appreciate the help.

Thanks