7.5 woes

[WTF]

First off- I have a new vibration/ growl combination going on under the truck. It's not u-joints or binding of any kind (it's totally stock). I'm using Royal Purple Max Gear in the diff as I have for years with no issues. So, what would you guys consider to be too much weight for a 7.5 equipped Ranger? Does 1140 lbs sound like too much? If so, what's the most likely victim to replace- the bearings and seals or just junk it and get an 8.8?

 

[dla]

My guess would be that the rear axle bearings, (passenger side), are worn out. Put your foot on the top of the tire and give it a shove. If you hear it rattle, then be suspicious. If you jack it up and can move the rear tire up and down 1/2", you probably need to look into new bearings.

To do the job yourself you will need a bearing puller and 5lb slide hammer for removal. You can buy the axle saver replacement bearing (one piece that includes seal) if your axle bearing surface is less than perfect.

A shop here charges $250 for one bearing. Might as well do both since you've got the diff drained.

Note: Ford uses good bearings (Timken). Don't put ccc* bearings back in, (or let a shop put them in).


*cheap china crap

 

[mhughes165]

thats not too much weight, but id still put in a 8.8 before fixing a 7.5 because of how common the 8.8 is

 

[WTF]

I figure the 8.8 is the right way to go as well rather than spend dinero on 7.5 parts. Prior to my first post, both axle shafts have the slightest lateral movement which indicates the bearings are done. I don't have any gear oil coming out of the axle seals yet so I'm not in a hurry to work on it. My concern was more towards the chances of having bent both axle shafts due to overloading it so I could be confident in buying an 8.8 and not wasting time on the 7.5. I guess I should have been more clear on my first post. I figured more than just two RS members have actually used their truck to haul stuff and had experienced this issue. Thanks guys

 

[4x4junkie]

Remember that the Ranger 8.8" (28 spline) and the 7.5" have the same shafts, so one will not carry more weight than the other.

I do agree however that 1140lbs shouldn't have been a problem. I would say either lack of lube did it in (low oil level), or maybe it was just it's time to go.

 

[WTF]

Thanks for the response Junkie. It definitely wasn't low on gear oil. I believe you're right.... that it's just time to go out. It's a 20 year old truck and I'm the second owner and I bought it when it was 18 years old. The first owner was meticulous about the truck going to the Ford dealer for EVERYTHING. I had a 3 inch file of receipts to prove it; just couldn't see holding onto that file since I'm gonna drive it until it turns to dust. Every part I've replaced has been a Ford or Motorcraft part so that leads me to believe it's an original part or a 5-10 year old replacement part, right? I don't know if the rear axle bearings and seals have been replaced though. Guess I get to go buy a slide hammer then.

I guess I should've combed through that file better before I tossed it out.

 

[dla]

bearings get really noisy before they're "done". A slight amount of lateral movement is normal. The axle bearing is a flat roller, so you're not going to feel much lateral movement. But you will feel the up/down movement when you jack it up.

Personally, you gain nothing with a 28spline 8.8. I would rather put bearings in a known rearend than roll the dice with a junkyard special. If you want extra capacity you'll need to move up to 31spline 8.8.

 

[WTF]

I agree with ya there. You never know what you're getting out of the yards. I'm gonna change out the carrier first. It's not in the shape I expect anyway plus get a closer look at the u-joints while I'm at it. Thanks again for the input fellas.

 

[WTF]

Carrier bearing was the culprit.

 

[strvger]

glad you got it fixed!

 

[feellnfroggy]

Personally, you gain nothing with a 28spline 8.8. I would rather put bearings in a known rearend than roll the dice with a junkyard special. If you want extra capacity you'll need to move up to 31spline 8.8.

Serious? You gain strength and greater options for lockers, carriers, axles and such. A 28 spline 8.8 has the same axleshafts as the 7.5, however the housing itself is stronger. As far as I know with an 8.8 even 28 spline you can swap in the 31 spline carrier, and shafts. You can use larger gears even with 28spline. this alone is a great benefit.

 

[4x4junkie]

You cannot swap 31 spline shafts into a 28 spline housing unless the shafts are custom-made with bearing journals to fit the 28 spline housing (which removes the weight carrying benefit you'd otherwise have with an OE 31 spline setup).