K1500 Steering Box Upgrade

[Schurkey]

Have an 88 K1500 with 300,000 miles. Plain old power steering, not Hydroboost or electronically-variable assist.

Steering gear is worn-out, has excess play. Difficult to drive "straight", have to saw the steering wheel back and forth to keep the tires pointed where I want.

I can easily find a plain old steering gear for this unit, but I'd like to know if there's a "special" gear that would fit. Perhaps a faster-ratio gear was used on some models.

Does anyone know of steering gear differences (Ratio, or steering effort/steering gear torsion bar size) on the '88--98 C/K trucks?

[Schurkey]

Searched part numbers at NAPA (www.napaonline.com)

Seems the same basic steering gear design is used on 1988--2000 vehicles including C/K pickups, Suburban, Blazer, Yukon, Tahoe, and even some Dodge Ram trucks, including 1/2, 3/4, and 1-ton vehicles.

In my search, four part numbers show up for these vehicles from 1988 to 2000. All have three mounting bolts, the same plumbing threads (M18 X 1.5; M16 X 1.5), the same size input shaft (3/4"), the same diameter output shaft (1 1/4") and the same spline count (32). In short...should be interchangeable.

NSP 88278091 = the one specified for my truck (88--95 C/K1500, and others)
Gear box turns = 2 5/8--3 1/16

NSP 88278117 = 1996 C/K, various Suburban, Tahoe
Gear box turns = 2 5/8

NSP 88278090 = 1997--2000 C/K, various Suburban, Tahoe, Ram
Gear box turns = 3 -- 3 1/2

NSP 88278127 = 1999--2000 Escalade, 1998-1999 C/K and Suburban, 1998--2000 Tahoe
Gear box turns = 3 1/16

www.napaonline.com does not list information such as torsion bar diameter and gear RATIO. Implying gear ratio from the gear box turns lock-to-lock is extremely imprecise because some steering boxes have internal stops and others don't. Boxes without internal stops rely on the steering knuckle bumping against something (typically a reinforcement on the lower control arm) to limit steering travel. In this case, I suspect that these boxes are not internally-limited, and the various chassis designs determine the turns lock-to-lock. That's the only thing that makes sense to me, because the boxes shouldn't have more than one figure quoted for turns otherwise.

With the limited info presented, it looks like the box specified for my truck (NSP 88278091) IS the best choice, that or the 1996-spec NSP 88278117. I have absolutely no idea what's different between the two. Perhaps the torsion bar.

ANY OTHER INPUT on steering gears for C/K trucks???

[dusty3]

Maybe you have already tried this, but I will suggest it anyhow. On the top of the steering box there is a allen head stud that sticks out from the box with a jam nut on top. You can tighten the loose play by putting an allen head wrench in the allen hole, then loosen the nut, make sure that you hold allen wrench in exact position it is in. After looseing the nut a couple turns, you can tun the allench clockwise about a 1/4 of a turn, Tighten the jam nut and check input play. The most I have ever turned one is 2 rounds. Continue making small adjustments until the input shaft slack is almost gone. Note; do not over tighten allen bolt or steering will be hard and may lock.

[webbch]

Until recently, I was having to do the 11:00 to 1:00 constantly on the steering wheel while driving on the highway to keep her going straight. New rag joint for a couple bucks, and tightened up the steering gear like dusty3 recommended above, and it's MUCH tighter. There's still wear in the steering gear, but at least I don't have to be rocking the steering wheel like before.

The only difference in the procedure I did for tightening the steering gear was to loosen the locknut, then run the allen screw down until snug, then backed it off a tiny bit (~1/16" to 1/8"). Originally, I didn't back it off at all, and on my test drive it didn't feel right - too tight. Backing it off just a tad really made a big difference.

A little tip to avoid breaking the plastic cover that goes over the rag joint is to use a heat gun on the plastic where it snaps over the power steering line. That softens it up enough to remove without breaking off the tab.

[Schurkey]

Originally Posted by webbch

Until recently, I was having to do the 11:00 to 1:00 constantly on the steering wheel while driving on the highway to keep her going straight. New rag joint for a couple bucks, and tightened up the steering gear like dusty3 recommended above, and it's MUCH tighter.

FINALLY got around to swapping steering gears. Seems to be a little tighter, but not as much as I had hoped. Having looked under the plastic sleeve, the rag joint seems to have about an eighth-inch play in it.

HOW did you replace the rag joint? Dorman $11 rag-joint kit, drill the rivets, replace with parts in the kit? Or did you find the now-discontinued shaft assembly from GM parts?

I'm a little shy about grinding/drilling the riveted assembly; I can't see well enough into the Dorman kit to verify that there's bolts or new rivets or whatever to re-assemble the thing.

[ASJT3]

Originally Posted by Schurkey

FINALLY got around to swapping steering gears. Seems to be a little tighter, but not as much as I had hoped. Having looked under the plastic sleeve, the rag joint seems to have about an eighth-inch play in it.

HOW did you replace the rag joint? Dorman $11 rag-joint kit, drill the rivets, replace with parts in the kit? Or did you find the now-discontinued shaft assembly from GM parts?

I'm a little shy about grinding/drilling the riveted assembly; I can't see well enough into the Dorman kit to verify that there's bolts or new rivets or whatever to re-assemble the thing.

It's a PITA to grind off the rivets. I've replaced rag joints twice, both times used a dremel to grind off the rivets and both times using the dorman kit. It takes a while for the grinding - probably around a half hour at least, and I went through a decent amount of cutoff wheels.

Both times I used stainless steel bolts and nuts to attach the two ends of the coupling, I still don't understand the hardware that's included in the kit (and I believe they only include two shoulder bolts whereas you need 4 ).

Anyways, I think I remember reading somewhere on here that you should use bolts with a shoulder so that you can torque down tight, I've used double nuts with a lockwasher in between (nylon nuts would probably work well too). In any case make sure to use some sort of locking device - I got cocky on my 2nd install and used only one nut with no locking and a week or two later I checked on it after the steering was getting very sloppy and discovered that only one bolt out of 4 was still attached

Clearance is tight on the coupling, will probably have to use 2" long 3/8" bolts IIRC.

[Schurkey]

THANK YOU.

Dorman rag joint kit is stocked locally. I'm going to find another shaft assembly to install it onto. I want to end up with a satisfactorily-rebuilt shaft without taking the vehicle out of use. Then I can just swap the original shaft for the rebuilt one. Project is officially on "hold" until warmer weather.

[TiVoPrince]

Recently
completed the 300,000 changeover. Replaced the badly worn and seeping steering gear.

Wanted the 2.5 turn box. Got a 3 turn box, returned that. Took along the intermediate shaft to show that it was not the specified 2.5. This was after trusting the store and completing install. Took almost three weeks to get a true sport steering box. Checking every local stoore yielded a few 3 1/8, loads of 3.0, and a few 2 3/4 identified as sport steering boxes. Somewhere along the way a store called with the "holy grail" 2 5/8 gear. This is because they have respecified 2.6 as the "new standard" on thier website. Along the way i have climbed the corporate ladder to find someone to help. Eventually at the corporate office put me in touch with a kindred spirit who works at the rebuilder. I learned a lot, especially to be kind and always be persistent.

After almost three weeks I'm back in business with a wide stupid grin on my face. Now I'm thinking about DJM lowering front an rear 2 inches. Any more drop and I can't get it up my driveway.

The rag joint long ago was replaced with a double u-joint intermediate from a Jeep Grand Cherokee. Unless you want a nervous, jumpy and fidgety driving experience rebuild the rag joint. I like the precision and incredibly accurate point and shoot like driving a Lamborgini in a video game.

This is not the truck you want to drive cross country. When your vehicle gets 12MPG on a good day, it had better be incredibly fun to drive every day...

[Schurkey]

What brand and what part number for the steering box?

How does the JGC double-U-joint shaft install? Bolt in, or mods required?

[TiVoPrince]

Part
numbers are a bit of challenge.

AutoZone lists 3.0 steering boxes as part number 7539. I found mostly 3.0 and 3.1 in my limited (less than 10) experience of actually trying what is in the boxes. This includes expeditions to Advance and NAPA as control sources. The "2.5" is part number 7551 and what I eventually bought. Of more than five at the store there was one 2.6, and a few 2.75, with a fair number of 3.0 in the mix.

O'Reilly also lists 503-0129 for 3.0 steering boxes and for the most part they were all correct. Part number 503-0182 is listed as 2.5 but the only one in the local parts inventory was 2.75 in actual testing.

Jeep shaft required no mods at all. Confirmed that donor had Saginaw steering box just like in GM vehicles. IIRC it was a 2002ish model with the open frame universals because I had some concerns that the universals with greater mass might bind in practice. After install I don't think it mattered all much in the end. The upper end of the shaft is not pinned through the stub like the original. Over time I have checked the torque on that 13mm bolt and it seems to stay tight to the point I will probably discontinue that practice now.

Loosen top of shaft and collapse it to get it free. Screwdriver through the universal and a couple of light taps did the trick. Unbolt the bottom at the steering box, rust may make this a struggle. I found that a plain old construction pry bar was helpful to encourage releasing it without damage. There were a lot of jeeps and GMtrucks suffering with serious extraction butchery, so select your victim carefully.

While I expect this to be my lifetime solution on this truck, if I were doing it again it would pay benefits to rescue a sport steering 2.5 box from a dismantling yard. Having that "rebuildable" core at hand along with the spare shaft to turn it so you really get what you want right out of the gate. Love folks at parts stores like family, but they need to be educated in the fine points of thinking things through without living by whatever the parts computer says.

Now I'm thinking DJM control arms with a 2inch lowering front and rear. Can't do much more and reliably get in and out of my driveway...

[Schurkey]

Originally Posted by TiVoPrince

Part
numbers are a bit of challenge.

AutoZone lists 3.0 steering boxes as part number 7539. I found mostly 3.0 and 3.1 in my limited (less than 10) experience of actually trying what is in the boxes. This includes expeditions to Advance and NAPA as control sources. The "2.5" is part number 7551 and what I eventually bought. Of more than five at the store there was one 2.6, and a few 2.75, with a fair number of 3.0 in the mix.

O'Reilly also lists 503-0129 for 3.0 steering boxes and for the most part they were all correct. Part number 503-0182 is listed as 2.5 but the only one in the local parts inventory was 2.75 in actual testing.

Yes, I understand all about parts "fitting" but not being rebuilt with the correct ratios and torsion bars that the item should have had.

Originally Posted by TiVoPrince

Jeep shaft required no mods at all. Confirmed that donor had Saginaw steering box just like in GM vehicles. IIRC it was a 2002ish model with the open frame universals because I had some concerns that the universals with greater mass might bind in practice. After install I don't think it mattered all much in the end. The upper end of the shaft is not pinned through the stub like the original. Over time I have checked the torque on that 13mm bolt and it seems to stay tight to the point I will probably discontinue that practice now.

Loosen top of shaft and collapse it to get it free. Screwdriver through the universal and a couple of light taps did the trick. Unbolt the bottom at the steering box, rust may make this a struggle. I found that a plain old construction pry bar was helpful to encourage releasing it without damage. There were a lot of jeeps and GMtrucks suffering with serious extraction butchery, so select your victim carefully.

While I expect this to be my lifetime solution on this truck, if I were doing it again it would pay benefits to rescue a sport steering 2.5 box from a dismantling yard. Having that "rebuildable" core at hand along with the spare shaft to turn it so you really get what you want right out of the gate. Love folks at parts stores like family, but they need to be educated in the fine points of thinking things through without living by whatever the parts computer says.

I think I was holding that U-joint shaft in my hand when I scavenged a JGC steering box for my El Camino. Left it with the Jeep. Could have had it for free. Might be that the JGC was an earlier generation, though. I'm thinking '90s, not 2000-ish.

For the record...I'd love to see photos of the Jeep shaft installed in your truck.

[TiVoPrince]

Time
was not my friend this week. Photos of top and bottom of shaft. Hopefully shows the details you seek. While nothing really interferes there are few good camera angles to show details.

Auto parts stores appear to be making up their own rules these days. Having that "Meets or exceeds OEM quality" on the label doesn't mean much when they are inventing their own standards. GM had 2.5, 3.0 and 3.1 turns lock to lock. The invention of 2,6 and 2,75 make me wonder what exactly the standard is if its not the GM design with whatever safety and durability improvements have been found over the years. This is what those bullet points on the box infer but the legalese behind those statements mean whatever a lawyer can twist them into. Placing a number in the specifications that is not the OEM value is just another little sleight of hand to sell more stuff, or pull cost out of the rebuilding.

Meanwhile I'm driving around with a big stupid grin on my face. Folks at the stoplight next to me must think i have gone barking mad. Or maybe I was hit on the head with a coconut. Don't care, the fun that wandered away a couple of years ago is back and I'm happier with my old truck than the mustang rental car I had on a recent trip.

The wayward steering is solved. Precision rules the day. I'm making a thousand little (1 or 2 degree) corrections every mile just like a quality sports car. And now im loving every minute of the driving experience. Truck may get lousy gas mileage, but its fun to drive again and that makes it worthwhile...

[Schurkey]

Originally Posted by TiVoPrince

Meanwhile I'm driving around with a big stupid grin on my face. Folks at the stoplight next to me must think i have gone barking mad. Or maybe I was hit on the head with a coconut. Don't care, the fun that wandered away a couple of years ago is back and I'm happier with my old truck than the mustang rental car I had on a recent trip.

The wayward steering is solved. Precision rules the day. I'm making a thousand little (1 or 2 degree) corrections every mile just like a quality sports car. And now im loving every minute of the driving experience. Truck may get lousy gas mileage, but its fun to drive again and that makes it worthwhile...

My hat's off to you, dude. You're where I want to be with the steering on my truck. I've just been so lazy as to complain about it for years, but not do anything (effective) yet.

You're also entirely accurate about the crap coming out of the "Rebuilt" as well as the "New" boxes on the parts-store counters. In particular, "New" doesn't mean "Good" when the Chinese are involved.

[TiVoPrince]

Caveat Emptor
or "let the buyer beware" is the watch phrase for this. I'm not certain that we should blame the rebuilders who seek to reduce costs or the parts stores who drive them for ever greater discounts. We are tremendously spoiled by the availability of cheap parts from unknown sources because we value price over quality or longevity in too many cases.

ATSCO who made my rebuilt 7551 box in Mexico may be the victim of the requirements set by stores for ever lower prices. Visiting a web "superstore" I find that they are $60 higher than the AutoZone price with a hefty up charge for the core. Given the ordeal and my time invested, the $60 plus shipping would have been the preferred option if I had done more research.

Complaining about cheap stuff is a national pastime that in many cases we have brought onto ourselves. I'm guilty of price shopping, my bride refers to me as Benjamin Franklin thrifty. I'm not a miser, cheapskate or tightwad but a value shopper who values a good deal but not at the expense of getting it right. If you are repairing an old truck to get another year out of it that is far different than my theory that I don't want to be doing the same repair in two years time. Parts stores have identified old truck owners as being a high percentages of folks who are doing DIY repairs to limp along until the vehicle dies. Just because we want quality parts it does not necessarily make us willing victims of vehicle repair show sponsors.

While I don't know if this is necessarily helpful for 4WD K series since GM never catalogued sport steering with 4WD to my knowledge. I can't see where 2WD sport steering gears would not work in a 4WD but in the infinate wisdom of GM they did not build this combination. There may be stresses at work that are not apparent to someone like me who only holds a hammer and nail degree from the university of driveway arts...

[Schurkey]

Originally Posted by TiVoPrince

Caveat Emptor
or "let the buyer beware" is the watch phrase for this. I'm not certain that we should blame the rebuilders who seek to reduce costs or the parts stores who drive them for ever greater discounts.

Selling a "rebuilt" part that does not meet the specs of the original--while being packaged in a box that has "Meets OEM Specs" printed on it is outright deceptive advertising. There should be fines and prison time involved.

OTOH, when folks turn in an improper core, the folks at the parts counter should be sharp enough to (usually) figure out that it's wrong, and discount the core value accordingly. This would require people at the parts counter smarter than the box the part is packaged in, and with time to actually inspect the item--and that isn't likely based on the parts-counter people I "train" when I go to the various parts stores.

Originally Posted by TiVoPrince

There may be stresses at work that are not apparent to someone like me who only holds a hammer and nail degree from the university of driveway arts...

Thanks for that. "University of Driveway Arts": I love it.

Is your "sport" box smaller or of an obvious main-casting difference from the original? I assumed the box was the same, but with different gears inside.

When I got up the gumption to change boxes on my truck, I attempted to install a JGC steering box--took about fifteen seconds to figure out that the JGC box was smaller, and had a different mounting bolt arrangement. There was no way the JGC box would fit my '88.