Damaged Saginaw Steering Gear Part

[dawson357]

Decided to tackle a rebuild of my power steering gear box. Watched several videos and got a lot of good tips. Things were going well until I discovered a gouge in the race of the adjuster plug where the seal sits. Probably why it had a slow drip leak. Gently ground the high points off but the mark is still there. Might be OK with new seals but still bugs me. I found a replacement part on ebay but it's for a GM Saginaw 800. From what I've read, many parts are interchangeable and this one looks identical to mine. With shipping it's 50 bucks. (Part #58686866) Your thoughts?

 

[Stanglover]

The box on our Mustangs IS a Saginaw 800and are in fact GM boxes. The difference is in the mount points on the casting. The internals are basically the same except for ratio, variable or fixed. The sector shaft will be different depending on the vehicle it was intended for.
That damage looks like someone tried to pry out a seal. Probably a good idea to replace it, but it possibly could be "fixed" using Loc-Tite seal retainer ( NOT thread locker!!). If it were mine, I'd replace it.
I'm no expert, but I've rebuilt 3 or 4 PS boxes to date. The other major area of concern is the sector shaft lower seal area. If it's scored, you're not likely to find one unless you can find a machine shop that can get it repaired by hard chroming and regrinding the OD.
I have to leave this here for now, I'll be back if you need more info.

 

[Bentworker]

There are different OD sizes of input shafts on the 800 boxes. The newer ones are smaller. I’d ask the seller to measure it for you. The earlier ones are 13/16” (71-73 mustangs). A ton of the GM boxes are 3/4”

 

[dawson357]

Thanks for the info Stanglover and Bentworker! Will help a lot.
Learning as I go. That's part of the fun.

 

[Stanglover]

There are different OD sizes of input shafts on the 800 boxes. The newer ones are smaller. I’d ask the seller to measure it for you. The earlier ones are 13/16” (71-73 mustangs). A ton of the GM boxes are 3/4”

Ah, yes. Good point.

 

[Stanglover]

Bentworker has vastly more experience than do I and in fact much of what I have come to learn was from his experiences. Watching videos was also a big help, but you'll soon figure out which are good and which are just someone wanting to make a video just to make a video.
If your PS box has little ware and very little free paly on the steering wheel, a reseal and reassembly will likely be all you need and is doable. If you need to reduce free play, then it gets a little more complicated as replacement of the circulating balls is needed. Finding those is quite difficult, but there are companies who sell precision ball bearings to 5 decimals.
You will also need a couple of specialty tools. A low range inch/pound beam wrench is vital to set the preload on the input shaft thrust bearing and to set the overall sector shaft preload. The Ford Mustang manual (mine is a 71) shows in detail how to do this. Try www.chevelles.com/techref/PowerStrgGear(1).jpg and (2).jpg. It shows in good detail how to disassemble and reassemble the steering gear. Not to overwhelm you at this point, take your time and you'll be ok. Ask at any point.
In the meantime, here are a couple of pics to explain a few things. Pic 1613 shows a badly scored sector shaft. This will need to be repaired or it will leak. Pic 765 is the thrust bearing preload of about 3 in/lbs.
Also a search will bring up lots of past threads and post on this subject.

 

[dawson357]

Bentworker has vastly more experience than do I and in fact much of what I have come to learn was from his experiences. Watching videos was also a big help, but you'll soon figure out which are good and which are just someone wanting to make a video just to make a video.
If your PS box has little ware and very little free paly on the steering wheel, a reseal and reassembly will likely be all you need and is doable. If you need to reduce free play, then it gets a little more complicated as replacement of the circulating balls is needed. Finding those is quite difficult, but there are companies who sell precision ball bearings to 5 decimals.
You will also need a couple of specialty tools. A low range inch/pound beam wrench is vital to set the preload on the input shaft thrust bearing and to set the overall sector shaft preload. The Ford Mustang manual (mine is a 71) shows in detail how to do this. Try www.chevelles.com/techref/PowerStrgGear(1).jpg and (2).jpg. It shows in good detail how to disassemble and reassemble the steering gear. Not to overwhelm you at this point, take your time and you'll be ok. Ask at any point.
In the meantime, here are a couple of pics to explain a few things. Pic 1613 shows a badly scored sector shaft. This will need to be repaired or it will leak. Pic 765 is the thrust bearing preload of about 3 in/lbs.
Also a search will bring up lots of past threads and post on this subject.

Much appreciated. You guys are great.

 

[machattack]

Decided to tackle a rebuild of my power steering gear box. Watched several videos and got a lot of good tips. Things were going well until I discovered a gouge in the race of the adjuster plug where the seal sits. Probably why it had a slow drip leak. Gently ground the high points off but the mark is still there. Might be OK with new seals but still bugs me. I found a replacement part on ebay but it's for a GM Saginaw 800. From what I've read, many parts are interchangeable and this one looks identical to mine. With shipping it's 50 bucks. (Part #58686866) Your thoughts?

View attachment 79231View attachment 79233View attachment 79234View attachment 79235

If you get ahold of RED HEAD steering gears they will sell you a O.E part. They just rebuilt my P.S box and did a great job.
Daniel Foster

[email protected]

1 800 808 1148 ext. 100

206 364 3333

Direct Line – (208) 449 1491

 

[dawson357]

If you get ahold of RED HEAD steering gears they will sell you a O.E part. They just rebuilt my P.S box and did a great job.
Daniel Foster

[email protected]

1 800 808 1148 ext. 100

206 364 3333

Direct Line – (208) 449 1491

Great! I'll give them a call tomorrow. Thanks

 

[Stanglover]

Don't forget, if in doubt ASK.
One tip I just thought about and that is when you want to install the teflon seal ring on the rack piston, wrap it with electrical tape, 2 or 3 turns, then use a 3 -4" gear clamp and carefully tighten just enough to compress the seal ring, then put it in a fridge, even overnight. When you come to install the rack piston, there is a very sharp edge on a fluid return hole. This will for sure cut the seal ring. So, before you try anything, deburr that hole. I use a small piece of plastic film strip, something from a packaging item works, but it must be thin yet stiff enough to hold its shape. Apply some grease to the hole area and set the film strip over the hole. The idea is to stop any possibility of cutting the seal. While the piston is still cold, remove the clamp and tape, then install the rack piston slowly while you guide the seal over the film strip. With any luck, the piston will slip in without damage. You get one shot at this, a reason I buy two kits at a time. I did however find I could buy the same teflon seal from my local industrial bearing supply company. Handling these teflon seal is tricky and delicate work, DO NOT RUSH!!
Unfortunately, I don't have any pics of that area. Why I don't know!
If this seems all too complicated for you, others have had good results buying complete rebuilt and/or upgraded to fast ratio boxes, from RedHead steering.

 

[dawson357]

Don't forget, if in doubt ASK.
One tip I just thought about and that is when you want to install the teflon seal ring on the rack piston, wrap it with electrical tape, 2 or 3 turns, then use a 3 -4" gear clamp and carefully tighten just enough to compress the seal ring, then put it in a fridge, even overnight. When you come to install the rack piston, there is a very sharp edge on a fluid return hole. This will for sure cut the seal ring. So, before you try anything, deburr that hole. I use a small piece of plastic film strip, something from a packaging item works, but it must be thin yet stiff enough to hold its shape. Apply some grease to the hole area and set the film strip over the hole. The idea is to stop any possibility of cutting the seal. While the piston is still cold, remove the clamp and tape, then install the rack piston slowly while you guide the seal over the film strip. With any luck, the piston will slip in without damage. You get one shot at this, a reason I buy two kits at a time. I did however find I could buy the same teflon seal from my local industrial bearing supply company. Handling these teflon seal is tricky and delicate work, DO NOT RUSH!!
Unfortunately, I don't have any pics of that area. Why I don't know!
If this seems all too complicated for you, others have had good results buying complete rebuilt and/or upgraded to fast ratio boxes, from RedHead steering.

Thanks Stanglover. Grateful for all these tips. I have everything ready to go. I saw a video of the taping of the teflon rings and will give it shot. Also felt the burr you are talking about. I did buy 2 rebuild kits just in case. I'll give a post when I complete the task. It will be some time before I get to install it. Getting ready for the FMX to toploader switch and have to move the headers out of the way. This gear sits about 1/32" away from the header. I'm rebuilding components like this as I go so they'll all be ready when it goes back together. I'll be quite happy if nothing leaks or comes apart when I fire it up.

 

[Stanglover]

Thanks Stanglover. Grateful for all these tips. I have everything ready to go. I saw a video of the taping of the teflon rings and will give it shot. Also felt the burr you are talking about. I did buy 2 rebuild kits just in case. I'll give a post when I complete the task. It will be some time before I get to install it. Getting ready for the FMX to toploader switch and have to move the headers out of the way. This gear sits about 1/32" away from the header. I'm rebuilding components like this as I go so they'll all be ready when it goes back together. I'll be quite happy if nothing leaks or comes apart when I fire it up.

Good stuff! Keep us informed and like I said, if in doubt ask first. We may not have all the answers, but ya never know.

 

[Stanglover]

@dawson357
Send me a PM to Stanglover.
I found I have a spare adjuster plug if you still need one. I can install a new bearing and seals.
I tried to send a PM (Conversation) to you, but it will not accept your user name. I see you are you a registered member?