1979 Pitman arm replacement trouble
#1
Competitively Average
Thread Starter
1979 Pitman arm replacement trouble
I am in the process of freshening up everything on my 1979 rx7, but This pitman arm is giving me hell! I got the old one off the box without a problem and found a replacement Centric brand one on rock auto and it fit but it didn't slide on the spline nearly as far as original so I attempted to push it the rest of the was on with the nut and striped out the treads (terrible idea I know) luckely I had a spare box with a good shaft, so I replaced that and ordered another arm Rare Parts brand or somthing like that and it still stoped very low on the spline compare to the one I took off! anyone else have this problem?because I just can't seem to find any other arms
Original arm
New arm
New arm
#3
Senior Member
#5
Village Idiot
iTrader: (8)
Unfortunately, I have to replace my steering gear and am in the market for a replacement, which means you will have an opportunity to figure this out before I do.
#6
Full Member
I am having similar issues with the pitman arm on my '95 GSL. I used the puller tool to take the old one off and it worked like a charm. I've been tightening the new one on with a 250 lb-ft torque wrench and it looks like its only about 1/2 of the way on the splines. It's set to about 150 lb ft but I am applying more torque than that (it clicks every time I push)
I'm glad for the picture you posted of the original arm, I didn't note how far up the splines my original arm was, and I see now that it doesn't have to cover them completely. I'm certain I still need to torque it down more but I don't want to break anything. I decided that maybe the lock washer was making it hard for me to tighten down the arm, and I should go to the hardware store and get a flat washer to use just for pushing the arm on, then replace it with the lock washer. Maybe that will help?
What is the torque spec for the pitman arm nut? I can't seem to find it anywhere.
I'm glad for the picture you posted of the original arm, I didn't note how far up the splines my original arm was, and I see now that it doesn't have to cover them completely. I'm certain I still need to torque it down more but I don't want to break anything. I decided that maybe the lock washer was making it hard for me to tighten down the arm, and I should go to the hardware store and get a flat washer to use just for pushing the arm on, then replace it with the lock washer. Maybe that will help?
What is the torque spec for the pitman arm nut? I can't seem to find it anywhere.
#7
Full Member
Surely someone out there must have replaced their pitman arm successfully. How much torque is it supposed to take to get the pitman arm onto the sector shaft? I don't want to break anything. Am I missing a step?
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#9
Competitively Average
Thread Starter
It ended up being an improper fitment of the part. not torque specs. After ordering 2-3 from a few American companys I got one from japan...no good...Australia....no good. But the one from Greece did the trick. To be honest I have no real explanation for it beside the parts were made to incorrect specs. I know I ordered 2 from the guy when I got them I will look to see what brand they are
#12
Damn, it did start!
It ended up being an improper fitment of the part. not torque specs. After ordering 2-3 from a few American companys I got one from japan...no good...Australia....no good. But the one from Greece did the trick. To be honest I have no real explanation for it beside the parts were made to incorrect specs. I know I ordered 2 from the guy when I got them I will look to see what brand they are
#13
#14
Always Wanting to Learn
iTrader: (49)
It's simple math really, quality costs money. The more precise you are, the more expensive it will be to manufacture it. Problem is, quality is often sacrificed anymore (or relaxed) to make things more affordable for the customer and / or more profitable for the manufacturer. There are probably only a few actual manufacturers of the part, which several auto part suppliers all negotiate to buy from. It's a smaller world than most people realize.
#15
Waffles - hmmm good
iTrader: (1)
I wonder if its an SA thing, we have so many other weird issues with obscure fitment of parts like the threads on brake lines, clutch lines, etc.
I didn't replace mine when I refurbed all the other parts in my steering because it looked good and was nice and tight. Kind of glad I didn't do it yet. Now I know what to expect.
I didn't replace mine when I refurbed all the other parts in my steering because it looked good and was nice and tight. Kind of glad I didn't do it yet. Now I know what to expect.
#16
Damn, it did start!
After digging around I am not finding any catalog differences for the pitman between the SA and FB. That said, It seems that Centric #62045505 which is available almost everywhere is the same as O'Reilly's MasterPro K9142. At least the associated image looks the same. It also shares a similar price to Centric. However, Rare Parts #20512 looks to have a smoother casting and more quality behind it. It definitely seems to be cast and forged from different molds than Centric. Anyone tried the Rare Parts pitman arm?
#17
Casting is a process where molten metal is poured into a mold to cool and solidify. The advantages to this process is lighter weight and less machining than say a solid chunk of material. It's a good process for an engine block or rotor housing, but not for parts that are subject to high stress or loads.
Forging is done by heating up a solid piece of material and pounding it to shape with a die in a hammer forge. It compresses the molecular structure of the metal and make it extremely tough and durable. This is how the pitman arm blank is made. The seam you see on the side is not a parting line from a mold, but what is left after the blank was trimmed. When hammered, excess material is squeezed out between the top and bottom die cavity's After forming, the parts are placed in a trim die to cut this excess off, leaving a seam around the middle of the part.
From here, the blanks are machined which is what determines how it fits on the shaft. Although possible, I'm not sure that in an aftermarket situation, who ever machines the arms also has a forging capability. Large corporations like General Motors have enough resources to own and operate foundries and forge shops along side machine shops and weld / sheet metal fabrication but even GM have over time, outsourced this type of work to outside or overseas companies who provide it cheaper.
I guess my point is, aftermarket forgings can also come from more than a single source and would look different since they were made from different die's. They could also be sold to more than one manufacturer who performs the actual machining. So the "look" of the forging isn't necessarily a guarantee of how its machined. I will say that normally, Joe's machine shop would tend to purchase it forging blanks from the same source due to having a business relationship and / or geographic location. If Joe makes a good part, they would probably also consistently look the same. The trick is finding out, who is buying from Joe and stocking their warehouse.
Forging is done by heating up a solid piece of material and pounding it to shape with a die in a hammer forge. It compresses the molecular structure of the metal and make it extremely tough and durable. This is how the pitman arm blank is made. The seam you see on the side is not a parting line from a mold, but what is left after the blank was trimmed. When hammered, excess material is squeezed out between the top and bottom die cavity's After forming, the parts are placed in a trim die to cut this excess off, leaving a seam around the middle of the part.
From here, the blanks are machined which is what determines how it fits on the shaft. Although possible, I'm not sure that in an aftermarket situation, who ever machines the arms also has a forging capability. Large corporations like General Motors have enough resources to own and operate foundries and forge shops along side machine shops and weld / sheet metal fabrication but even GM have over time, outsourced this type of work to outside or overseas companies who provide it cheaper.
I guess my point is, aftermarket forgings can also come from more than a single source and would look different since they were made from different die's. They could also be sold to more than one manufacturer who performs the actual machining. So the "look" of the forging isn't necessarily a guarantee of how its machined. I will say that normally, Joe's machine shop would tend to purchase it forging blanks from the same source due to having a business relationship and / or geographic location. If Joe makes a good part, they would probably also consistently look the same. The trick is finding out, who is buying from Joe and stocking their warehouse.
#19
Damn, it did start!
the bushings? My concern is the age and mileage on my pitman. Why replace the entire steering linkage system and leave the main connection point untouched?
#20
Competitively Average
Thread Starter
I also had tried Rare Parts and yes it was a much nicer casting but wrong taper on the spline again, BUT! I talked to the guy who I ordered the proper fitting arm fromand I was able to get him to send me what he had left. They are new old stock that has been in GB for years . I have 6 of them if anyone would like me to send them one I can, i have pictures on my rebuild thread of what the original fit and aftermarket wrong ones are if your interested.