In need of a little help please.

[tongue_fu_master]

First off I would like to say hello to all my new friends I am going to make here.

As most, my first post is a request for help.

I have a 94 explorer xlt that is in need of a pinion shaft.
I noticed that the tires on the rear are not of the same size.
We have a 235 70 15 and a 235 75 15. Would this have caused the pinion shaft to snap? I was driving on a city street doing about 40 mph when it broke.

I am willing to bet some of you hardcore offroad guys have some of these pinion shafts laying around the shop and would be happy to hook a fella in need up.

The only other real issue with the truck is the fuel meter does not work. Aways reads empty. I am assumining this is going to be in the sending unit and will do a search on here for an answer.

Thank you all in advance.

Tongue_Foo

 

[IZwack]

Strange that you snapped the pinion gear with stock-ish tires. But perhaps you had the all-so-famous pinion bearing slop which eventually fatigued the pinion shaft which lead to the snap (as a loose pinion will wobble around in the differential and will have lateral stress applied to it every time the driveshaft rotates).

But as for replacing the pinion, unfortunately you first have to know the gear ratio of your vehicle as Explorers came with various gear ratios and one pinion gear of a specific ratio can not be used in another gear set of another ratio.

 

[tongue_fu_master]

Strange that you snapped the pinion gear with stock-ish tires. But perhaps you had the all-so-famous pinion bearing slop which eventually fatigued the pinion shaft which lead to the snap (as a loose pinion will wobble around in the differential and will have lateral stress on it every time the driveshaft rotates).

But as for replacing the pinion, unfortunately you first have to know the gear ratio of your vehicle as Explorers came with various gear ratios and one pinion gear of a specific ratio can not be used in another gear set of another ratio.

It is a 373 ratio.

I was not aware that the pinion shafts were different sizes according to the ratio.

Thank you for he quick response.

 

[IZwack]

I was not aware that the pinion shafts were different sizes according to the ratio.

I'm sorry I just realized that you may be talking about the center carrier pin. So the first thing is we have to make sure we're talking about the same part here.

The carrier pin (picture) is the somewhat large shaft (and vertical in the picture) that two of the spider gears are held on with and no it does not change from gear ratio to gear ratio (it is independent of gear ratios).

On the other hand, the pinion gear (picture - bottom part) includes the pinion shaft and therefore, the pinion shaft is dependent on the gear ratio of the vehicle.

Sorry that we still have to go through semantics but we have to make sure we're talking about th same part off the bat.

 

[tongue_fu_master]

I'm sorry I just realized that you may be talking about the center carrier pin. So the first thing is we have to make sure we're talking about the same part here.

The carrier pin (picture) is the somewhat large shaft (and vertical in the picture) that two of the spider gears are held on with and no it does not change from gear ratio to gear ratio (it is independent of gear ratios).

On the other hand, the pinion gear (picture - bottom part) includes the pinion shaft and therefore, the pinion shaft is dependent on the gear ratio of the vehicle.

Sorry that we still have to go through semantics but we have to make sure we're talking about th same part off the bat.

Carrier pin it is...Thank you.
All Data calls it a pinion shaft. I call it a headache..

Thanks again.

 

[IZwack]

Yeah different people call it different names but SummitRacing sells them for $15:
http://store.summitracing.com/partdetail.asp?autofilter=1&part=RMG-CSPF88L&N=700+115&autoview=sku

There are two pin diameters:
- 7/8" for 31 spline axle shafts
- 3/4" for 28 spline axle shafts

You want the 7/8" for 31 spline shafts -- for all Explorers. The 3/4" 28 spline is for the older Rangers.

 

[IZwack]

As for what could cause the shaft to snap:

Different tire diameters could definitely lead to excessive wear as the spider gears are rotating all the time when the vehicle is moving forward (with the exception of that slight turn which offsets the different tire diameter). Spider gears are not supposed to be rotating against each other when the vehicle is driving in a straight line -- only during a turn should they rotate.

When you do pull the pin out, you might even see excessive wear in the pin. If this is the case, then there also might have been excessive wear on the spider gear's inside diameter -- which means you probably need a new spider gear set:

If you have an open carrier (non limited slip), its $108 from SummitRacing but it also includes a carrier pin in the kit:
http://store.summitracing.com/partdetail.asp?autofilter=1&part=SAG-85-2013&N=700+115&autoview=sku
If you have an limited slip carrier, search around Google because the limited slip units have a different gear set that spline to the axle shafts.

 

[tongue_fu_master]

Yeah different people call it different names but SummitRacing sells them for $15:
http://store.summitracing.com/partdetail.asp?autofilter=1&part=RMG-CSPF88L&N=700+115&autoview=sku

There are two pin diameters:
- 7/8" for 31 spline axle shafts
- 3/4" for 28 spline axle shafts

You want the 7/8" for 31 spline shafts -- for all Explorers. The 3/4" 28 spline is for the older Rangers.

Mine has a couple of flat places on each side at the ends.

Here is a pic of it...can't see the flat areas but I am sure you know what I am speaking of.
Would the tires being off cause this to snap?

Thanks again
Tongue

 

[tongue_fu_master]

How hard of an install is this set?

Does the carrier have to come out of the rear housing?

 

[IZwack]

Okay wow amazing picture.

The spider gear set is not difficult to install and no the carrier does not need to come out.

I'm assuming you already have the spider gears out, so all you have to do is push the axle shafts back maybe 3 inches or so (to make room for the two spider gears that spline directly to the shafts). Remember that pushing the axle shafts out will mean removing part of the brake system (drums). Then you just have to play with the spider gears to get them in -- its tricky but not difficult. its been a while since I touched a set of spider gears but as I recall, you put the two side ones in, and then the top and bottom one are "swallowed" into the carrier by rotating the two side spider gears. Once all four are in, put the carrier pin, bolt it in and you should be good to go. Oh and remember there are bushings that go behind the spider gears.

But hey before you order that set, make sure you have a non-limited slip differential because having one of these, makes the job a little more difficult and technically, you should be ordering a different set of spider gears -- although the worn spider gears are the top/bottom ones and I think (but don't hold me against this!) these two spider gears are the same between the limited slip and non-limited slip (which means you can re-use the side spider gears since thats the only difference in the kit and these hopefully are not worn out). But I mentioned its a little more difficult because the limited slip carrier has clutch packs and one tough (as in pain in the ass to deal with) preloading "S" spring in the middle. If you didnt see this "S" spring when that carrier pin came out, then you have an open differential and that kit is what you need.

This is what the "S" spring looks like, although some are more of a square-ish "S" than others:

 

[tongue_fu_master]

Okay wow amazing picture.

The spider gear set is not difficult to install and no the carrier does not need to come out.

I'm assuming you already have the spider gears out, so all you have to do is push the axle shafts back maybe 3 inches or so (to make room for the two spider gears that spline directly to the shafts). Remember that pushing the axle shafts out will mean removing part of the brake system (drums). Then you just have to play with the spider gears to get them in -- its tricky but not difficult. its been a while since I touched a set of spider gears but as I recall, you put the two side ones in, and then the top and bottom one are "swallowed" into the carrier by rotating the two side spider gears. Once all four are in, put the carrier pin, bolt it in and you should be good to go. Oh and remember there are bushings that go behind the spider gears.

But hey before you order that set, make sure you have a non-limited slip differential because having one of these, makes the job a little more difficult and technically, you should be ordering a different set of spider gears -- although the worn spider gears are the top/bottom ones and I think (but don't hold me against this!) these two spider gears are the same between the limited slip and non-limited slip (which means you can re-use the side spider gears since thats the only difference in the kit and these hopefully are not worn out). But I mentioned its a little more difficult because the limited slip carrier has clutch packs and one tough (as in pain in the ass to deal with) preloading "S" spring in the middle. If you didnt see this "S" spring when that carrier pin came out, then you have an open differential and that kit is what you need.

This is what the "S" spring looks like, although some are more of a square-ish "S" than others:

what is in the photo is what mine looks like...The S spring is still in place and 2 of gears fell out and 2 are still in place.

 

[IZwack]

I tried searching for a spider gear set for the limited slip 8.8 but couldn't come up with anything.

I guess you can try calling one of the more famous gear outlets like Randy's Ring and Pinion to see if they have any. Or you can try a local Ford dealer.

As already mentioned, you can try the spider gear kit for the "open" differential and hope that the bottom/top gears are the same. You can also try hitting up a local junk yard. Or even post up a thread in the Wanted section of the forum.

I would go to the junk yard and pull a set for you but I am somewhat busy for the next week and a half at least. If you can wait that long, I'd be more than happy to pull a set for you.

 

[tongue_fu_master]

I tried searching for a spider gear set for the limited slip 8.8 but couldn't come up with anything.

I guess you can try calling one of the more famous gear outlets like Randy's Ring and Pinion to see if they have any. Or you can try a local Ford dealer.

As already mentioned, you can try the spider gear kit for the "open" differential and hope that the bottom/top gears are the same. You can also try hitting up a local junk yard. Or even post up a thread in the Wanted section of the forum.

I would go to the junk yard and pull a set for you but I am somewhat busy for the next week and a half at least. If you can wait that long, I'd be more than happy to pull a set for you.

I can definately wait but in the meantime I will post something in the wanted section.

Local junkyards won't open a good rear end up and part it out.

We don't have a pick and pull here or anywhere close by...

Thanks again for your help.

 

[IZwack]

Okay great, I'll let you know when I find some time to go to the junk yard. Right now I'm aiming for maybe April 5th or 6th.

 

[tongue_fu_master]

Okay great, I'll let you know when I find some time to go to the junk yard. Right now I'm aiming for maybe April 5th or 6th.

Thank you kind Sir.

 

[IZwack]

Quick question though -- when you removed the differential cover, was a sufficient amount of oil (maybe 2 quarts or so) that came out? Or was it maybe a cup or less?

 

[OldRedB2_84]

nice carnage!

if you look at the right half of that pin right where it broke you will see a brown spot, i bet that defect had something to do with it snapping.

 

[Jack Flash]

tongue_fu_master,

there's a wrecking yard in Kosciusko, MS that has several 91-94 explorers. you might give them a call if you're willing to buy a whole rear end.

Rawson's Auto Parts, (662) 289-5931, David Rawson.

maybe find other parts, if you need them.

I haven't been there lately, so call first to check availability.
.
.
.

 

[tongue_fu_master]

Quick question though -- when you removed the differential cover, was a sufficient amount of oil (maybe 2 quarts or so) that came out? Or was it maybe a cup or less?

Bout 2 qts in there.

 

[IZwack]

Oh ok -- just wondering if this whole thing was due to a dry differential.