Put an engine in a 94 F150 a couple weeks ago. Worst part was digging out SAE tools. Stuff that attached to the block or heads was SAE, rest was metric. Hodge podge of head sizes though.
Is it Metric or SAE guessing game
- Thread starter Chris142
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Problem for occurs when the head is obviously one type, yet when you go to clean the threads with a thread chaser ....
I don't recall 15mm heads on 3/8" bolts, But I do remember Torx drive on some 3/8" bolts in the TBI era & Double Studded bellhousing bolts being 3/8"-16 on one end & 8x1.25mm on the other...But had a 9/16" hex drive. Then a 13mm hex nut to secure the brackets.
Originally Posted by skyactiv
Didn't many GM automatic transmissions like the 700R4... go metric in the 80's and have METRIC stamped on the pan?
The 700R4 was 100% metric, But never had METRIC stamped on the pan. GM Hydramatic's like the TH200, 200-4R, 440-T4 etc had METRIC stamped in the pans. probably because the 700R4 wasn't engineered by the Hydramatic division.....It was engineered by the Chevrolet division. The TH350 wasn't engineered by Hydramatic either, Buick & Chevrolet divisions did that one.
GM still uses 5/16-24 u-joint strap bolts with a 7/16" head!
Didn't many GM automatic transmissions like the 700R4... go metric in the 80's and have METRIC stamped on the pan?
The 700R4 was 100% metric, But never had METRIC stamped on the pan. GM Hydramatic's like the TH200, 200-4R, 440-T4 etc had METRIC stamped in the pans. probably because the 700R4 wasn't engineered by the Hydramatic division.....It was engineered by the Chevrolet division. The TH350 wasn't engineered by Hydramatic either, Buick & Chevrolet divisions did that one.
GM still uses 5/16-24 u-joint strap bolts with a 7/16" head!
Yep, the 700R4 is definitely metric on my 89, as I had to use a 10mm socket to get the pan off when I did the transmission fluid/filter. All the suspension and brakes were still standard, though, as I going over the whole car after I purchased it a few years ago. Still remember having to get up and grab the metric sockets out my tool box for the transmission and being annoyed by it. Suppose I should have just gotten them both out like I do when I do anything on my 94.
Originally Posted by zrxkawboy
I remember similar fun when I owned a ‘98 Cherokee.
That was the first thing I thought of - my '88 Cherokee with a crazy mixture of standard, metric, and torx fasteners all over the place...
I remember similar fun when I owned a ‘98 Cherokee.
That was the first thing I thought of - my '88 Cherokee with a crazy mixture of standard, metric, and torx fasteners all over the place...
Worst I ever experienced was changing the clutch on a 2003 Jeep Wrangler. The bell housing was attached to the block by 6 bolts; two were SAE hex, grade 5 with 3 hash marks, two were metric hex, grade 10.9, and the last two were Torx. Was a real head scratcher.
To keep me from going crazier, I bought one bolt and one nut from 10-32 up to 3/4" and M3 up to M20 each in the different TPI, respectively. Got a cheap lure box at Wallyworld and put them in the bins with stickers on the bins to mark the sizes, and the wrench needed. My guessing days are over.
Originally Posted by LargestAl
To keep me from going crazier, I bought one bolt and one nut from 10-32 up to 3/4" and M3 up to M20 each in the different TPI, respectively. Got a cheap lure box at Wallyworld and put them in the bins with stickers on the bins to mark the sizes, and the wrench needed. My guessing days are over.
Thats one way to do it. Bought an SAE and metric thread gauge years ago and use them when working with a not readily recognizable thread size. Was working on an old Harley some years go which forced me to get those gauges. On that bike, the studs that held the lifter boxes on were 1/4-24. Was familiar with the common 1/4-20 and 1/4-28, but never had seen a 1/4-24.
Was wondering if that was a weird one off, but my Machinery's Handbook clearly shows it as legit, if not rather uncommon size.
To keep me from going crazier, I bought one bolt and one nut from 10-32 up to 3/4" and M3 up to M20 each in the different TPI, respectively. Got a cheap lure box at Wallyworld and put them in the bins with stickers on the bins to mark the sizes, and the wrench needed. My guessing days are over.
Thats one way to do it. Bought an SAE and metric thread gauge years ago and use them when working with a not readily recognizable thread size. Was working on an old Harley some years go which forced me to get those gauges. On that bike, the studs that held the lifter boxes on were 1/4-24. Was familiar with the common 1/4-20 and 1/4-28, but never had seen a 1/4-24.
Was wondering if that was a weird one off, but my Machinery's Handbook clearly shows it as legit, if not rather uncommon size.
Originally Posted by Tim_S
Worst I ever experienced was changing the clutch on a 2003 Jeep Wrangler. The bell housing was attached to the block by 6 bolts; two were SAE hex, grade 5 with 3 hash marks, two were metric hex, grade 10.9, and the last two were Torx. Was a real head scratcher.
I wouldn't put anything past a US automaker, especially Jeep, but I can't believe those were the factory-installed fasteners. What thread were the holes ? I didn't know fasteners with SAE thread and a metric head (or vis-versa) even existed until this thread.
Worst I ever experienced was changing the clutch on a 2003 Jeep Wrangler. The bell housing was attached to the block by 6 bolts; two were SAE hex, grade 5 with 3 hash marks, two were metric hex, grade 10.9, and the last two were Torx. Was a real head scratcher.
I wouldn't put anything past a US automaker, especially Jeep, but I can't believe those were the factory-installed fasteners. What thread were the holes ? I didn't know fasteners with SAE thread and a metric head (or vis-versa) even existed until this thread.
Originally Posted by hallstevenson
Originally Posted by Tim_S
Worst I ever experienced was changing the clutch on a 2003 Jeep Wrangler. The bell housing was attached to the block by 6 bolts; two were SAE hex, grade 5 with 3 hash marks, two were metric hex, grade 10.9, and the last two were Torx. Was a real head scratcher.
I wouldn't put anything past a US automaker, especially Jeep, but I can't believe those were the factory-installed fasteners. What thread were the holes ? I didn't know fasteners with SAE thread and a metric head (or vis-versa) even existed until this thread.
Those were the original factory fasteners. The Torx were a metric thread, as were the hex bolts marked with the metric grade designation. The SAE hex bolts were SAE thread. Thought I'd seen it all up until that point. What is even a bit more troubling, is metric grade 10.9 is way stronger of a bolt than SAE grade 5 too. No idea what strength the torx bolts were.
Originally Posted by Tim_S
Worst I ever experienced was changing the clutch on a 2003 Jeep Wrangler. The bell housing was attached to the block by 6 bolts; two were SAE hex, grade 5 with 3 hash marks, two were metric hex, grade 10.9, and the last two were Torx. Was a real head scratcher.
I wouldn't put anything past a US automaker, especially Jeep, but I can't believe those were the factory-installed fasteners. What thread were the holes ? I didn't know fasteners with SAE thread and a metric head (or vis-versa) even existed until this thread.
Those were the original factory fasteners. The Torx were a metric thread, as were the hex bolts marked with the metric grade designation. The SAE hex bolts were SAE thread. Thought I'd seen it all up until that point. What is even a bit more troubling, is metric grade 10.9 is way stronger of a bolt than SAE grade 5 too. No idea what strength the torx bolts were.
Originally Posted by hallstevenson
Tim_S said:
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Originally Posted by CR94
Originally Posted by hallstevenson
Originally Posted by hallstevenson
Tim_S said:
Originally Posted by Trav
Originally Posted by CR94
... Spark plugs had inch-sized hex with metric threads even further back.
Spark plugs have always used metric hex its just happens an SAE size will fit it. 12mm, 16mm (5/8), 18mm and 21mm (13/16) being the most common. The first functioning, patented and produced spark plug was from Robert Bosch in Germany which did not use SAE.
It was not always a case of "just happens" in USA. Before plugs started shrinking, spark plug sockets were labelled 13/16 inch, not 21mm, and fit with typical clearance on plugs. The same spark plug socket will barely fit on an actual 21mm nut, because the difference between 13/16" (=~20.64 mm) and 21 mm uses up almost all the clearance specified by standards. If the nut has a small burr, the socket won't go on. Conversely, a 21 mm socket would be a little sloppy on a 13/16" plug---although likely fit well enough to work if it's a 6-point.
I've seen spark plug sockets in metric sets labelled 20.6 mm---because they're designed for 13/16" hex.
You might be correct about the newer, smaller hex sizes.
We had a tractor that required a spark plug socket larger than 13/16, probably 7/8" ---not 22 mm..
Originally Posted by CR94
... Spark plugs had inch-sized hex with metric threads even further back.
Spark plugs have always used metric hex its just happens an SAE size will fit it. 12mm, 16mm (5/8), 18mm and 21mm (13/16) being the most common. The first functioning, patented and produced spark plug was from Robert Bosch in Germany which did not use SAE.
It was not always a case of "just happens" in USA. Before plugs started shrinking, spark plug sockets were labelled 13/16 inch, not 21mm, and fit with typical clearance on plugs. The same spark plug socket will barely fit on an actual 21mm nut, because the difference between 13/16" (=~20.64 mm) and 21 mm uses up almost all the clearance specified by standards. If the nut has a small burr, the socket won't go on. Conversely, a 21 mm socket would be a little sloppy on a 13/16" plug---although likely fit well enough to work if it's a 6-point.
I've seen spark plug sockets in metric sets labelled 20.6 mm---because they're designed for 13/16" hex.
You might be correct about the newer, smaller hex sizes.
We had a tractor that required a spark plug socket larger than 13/16, probably 7/8" ---not 22 mm..
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