360 Magnum

[AJ/FormS]

What! no LSD! lol,Yeah well then the 8.25 with no LSD may have peg-legged it's way into early retirement.
However,the over-running clutch, AKA sprague,is known to make an unusual sound when you put it into drive. Also the drive splines in the slip-yoke can make a creaking sound if somehow they run dry.The 904 can make several different sounds and seem to all be normal, including planetary gear whine.
And you might wish to check the trans mount while you're under there.
And if the noise hasn't shown up yet, I guess it's time to check the U-Joints.

 

[Bruceynz]

This is the kind of noise I hear but louder, check out the video

In neutral park brake on




Sorry about the grunt at the end, it was hard to get under and its 90F so I was struggling and cooking!

I am thinking the tinging noise I hear is when it changes down it unloads and loads up again making the drive shaft ring like a bell.

Trans mount new, universals new, I replace everything

 

[AJ/FormS]

90* @11:38! Whoa!!

I'm going with sidegear to pinion backlash; I don't think it's crosspin. It will diappear when you install the LSD,lol
I've seen a lot worse.
The only way to prove it from my side of the screen is to pop the cover and look.And then you might as well have spare washers on hand to tighten it up, cuz when it starts hammering on the crosspin like that,a big torquey 360 can,not will, spit out the crosspin before too long, and nobody can predict where that pin will go. It doesn't matter much tho cuz one thing is for sure; that whole rear end will usually lock right up and the wheels stop turning, instantly. Pray it happens in first gear while peg-legging, and pray harder it doesn't find the gastank.
But like I said yours ain't thaaat bad yet. Perhaps not bad enough yet to be able to fit second washers in.
So I do however recommend an inspection to be sure it's NOT a crosspin wallering out the case. If you find that, then stop driving it right away, and fix the case or replace it. I have had a machine shop successfully repaired a few cases,in 40 years.
No matter what you do; STOP peg-legging her. That's just begging for trouble. The case goes to double the indicated roadspeed on the speed-O, and all the power is spinning the pinions on the crosspin, making heat. And when the oil gives up,they seize to the pin,or try too. Then one day they do finally seize up tight and everything stops turning. And you can't believe how hard that makes disassembly. That crosspin has to come out, to make C-clip removal possible. Nothing happens until the crosspin comes out,Nothing. This is constipation of the worst kind.
But yours isn't thaaat bad........I don't think,lol

 

[Oldiron440]

It's time to find a limited-slip.

 

[Bruceynz]

No it was 90F when I went under the car at 5:30pm ish I didn't post to you straight away and not sure what time the post shows on your screen.

90* @11:38! Whoa!!

I'm going with sidegear to pinion backlash; I don't think it's crosspin. It will diappear when you install the LSD,lol
I've seen a lot worse.
The only way to prove it from my side of the screen is to pop the cover and look.And then you might as well have spare washers on hand to tighten it up, cuz when it starts hammering on the crosspin like that,a big torquey 360 can,not will, spit out the crosspin before too long, and nobody can predict where that pin will go. It doesn't matter much tho cuz one thing is for sure; that whole rear end will usually lock right up and the wheels stop turning, instantly. Pray it happens in first gear while peg-legging, and pray harder it doesn't find the gastank.
But like I said yours ain't thaaat bad yet. Perhaps not bad enough yet to be able to fit second washers in.
So I do however recommend an inspection to be sure it's NOT a crosspin wallering out the case. If you find that, then stop driving it right away, and fix the case or replace it. I have had a machine shop successfully repaired a few cases,in 40 years.
No matter what you do; STOP peg-legging her. That's just begging for trouble. The case goes to double the indicated roadspeed on the speed-O, and all the power is spinning the pinions on the crosspin, making heat. And when the oil gives up,they seize to the pin,or try too. Then one day they do finally seize up tight and everything stops turning. And you can't believe how hard that makes disassembly. That crosspin has to come out, to make C-clip removal possible. Nothing happens until the crosspin comes out,Nothing. This is constipation of the worst kind.
But yours isn't thaaat bad........I don't think,lol

 

[BudW]

I agree with AJ. Not considering the pin (just yet), it is time for a limited slip. 360 4-bbls need one to begin with. If you like smoking the tires – that is fine, but at least do both at same time. Having only one tire spin is VERY HARD on a differential and is only inviting $ trouble.

Another thing he said was if you were to experience troubles with that pin (inside of differential) – it can cause significant damage, even to the point the differential can not be taken apart (been there, done that as well I have seen it happen too many times to others).

For the most part, that pin does not cause much trouble for most people – but when it does, it does.

Several things can happen, one is the bolt that holds the pin in place, can snap (break) or loosen then comes out. Having that bolt (or part of the bolt) floating around in the lube right by the rotating gears is enough to hand grenade the differential (picture a big explosion).

Other times the pin bolt is fine/tight - but pin is loose inside of the case hole. The cast iron case (the part the ring gear bolts too and contains the spider gears) starts to waller out and the pin holes become egg-shaped (oval shaped). The cast iron case is softer than the hardened steel pin is. That allows iron shavings into the lube (not good on the gears) and will eventually cause the pin bolt to break from fatigue (which is bad news).

Also, if the pin is not stationary, it will come out of its hole. When that happens, it is like sticking a broom stick into a front motorcycle wheel at high speed (ie: very bad things are about to happen . . .).

I would recommend removing the cover (soon) to at least see what is up.
If pin is loose in case but not coming out, you can drive it for a short time while getting parts. If bolt is missing or broken – stop. If pin feels like is way loose in case – stop. If there are broken pieces inside – stop.


There are three major “limited slip” differential types for this car:
Cone type (the factory type), it is a cast iron cone rubbing against the cast iron case. Least expensive type, it works decent for most drivers. It is not rebuildable. It uses normal gear lube.

Clutch type. It uses fiber clutches and springs. It works well for gear heads like ourselves. This one can be rebuilt, if needed. Limited slip gear lube additive will be needed to prevent clutch chatter and for clutch life.

True-Trac (Eaton). It uses helical-gears to allow for smooth turns and to lock in place when needed. This is the most expensive version but I think is the best one for most drivers. This is the type I’m planning on getting. It uses normal gear lube.

I do recommend getting a bearing/seal kit at same time. You will have to replace the side bearings anyway. I would also recommend getting a differential shop to install the limited slip (and bearings). It can be done by self – but can be intimidating for first timers.
Many differential shops may require all bearings to be replaced. They may also supply their own (ie: not use yours).
BudW

 

[AJ/FormS]

Thanks Bud!

 

[Bruceynz]

Hi Guys,

I had the cover off it not long ago and it looked fine inside, I checked the back lash and it was all with in spec, I have a 8.25" rebuild kit in my parts bin so thats a bonus. Ratech Deluxe Ring and Pinion Installation Kits 3022K

Whats this one

POSI CARRIER DANA SPICER 27 SPLINE TRAC LOC DODGE CHRYSLER 8.25 INCH 10 BOLT | eBay

Thanks
Bruce

 

[Bruceynz]

Hello,

Ok I took my we Canadian friend for a ride who owns a Dodge Van with a magnum 360 back in Canada, he thinks the noise I hear is the trans changing down to 2nd gear with a clonk. Can this be possible?

Thanks
Bruce

 

[AJ/FormS]

Yes it is but it's rare.
More likely is
The noise from the rear-end clonk traveling up the driveshaft, which rings like a bell,or acts like a megaphone, and sounding LIKE it's in the trans.
But
Yes it is possible for the trans to make at least 3 or 4 different noises;some normal, but a clonk on the 3-2 downshift IDK ;that's a new one to me.
But I have some questions;
1) at what speed is this 3-2 downshift, and
2) is this an automatic downshift, or
3) is this a forced downshift, and
4) does it also do it on the 2-1 downshift

Make sure that trans is tied down at the back mount. I know you said the mount is good; but a too-hi road speed with a lift-foot downshift can produce a huge force on that mount, several hundred foot-pounds. This is enough to really move it around. Sometimes the cure is to bolt that big old counterweight back on, under the tail.

 

[Bruceynz]

Hmmmm when it changes down from 3rd to 2nd by itself, I don't recall hearing it do it when I manually down shift it from 3rd to 2nd.

 

[AJ/FormS]

Hmmmm, the clonk occurs when it changes down from 3rd to 2nd by itself.
I don't recall hearing it do it when I manually down shift it from 3rd to 2nd.

Did I understand you right?
Then,I'm gonna need to know at what roadspeed this clonk is happening, and if your foot is OFF the gas pedal.
If I understand you right;
By itself ;the trans should not backshift until just before you stop, maybe 8mph or less; and that depends on the rear gear. And, you should hardly feel it.And with a bit of a loose TC, it should be just perceptable.
I have a feeling she's running too much throttle pressure, probably because the TV ratio is not right yet.......But I'll wait for clarification.
Too much throttle pressure will cause a too-early downshift, and and when that happens the road speed will send torque up the driveshaft and attempt to increase the engine rpm. But the throttle is closed so it can't accomplish much. So instead the torque goes where ever it can: like into the TC and into the rear mount.
You did say the 904 had a kit in it right?
Did you put it in?
Do you still have the instruction sheet?
Does the trans auto-upshift at different and varying speeds depending on the amount of gas-pedal applied? In other words is the governor system still operating?
And are you happy with the auto-upshift points?

 

[BudW]

Yes, you need the 27 spline unit.
The newer ones (’97 and newer) use 29 spline axles – which axles are also larger in diameter at the spline area. The new ones (’97 and newer) also have electric engaged locking units and air actuated limited slip carriers - in addition to the options that we have.

The unit in the eBay listing is the clutch type.

After looking, I don’t see a True-Trac available for the 27 spline 8¼” differentials (which is a shame).
I would go with the eBay listing – or others like it.


Back to the clunk. Most clunk noises are nothing to be concerned with – but not all are to be dismissed.
With items being disturbed recently – most likely just a loose (or missing) bolt(s) or something like that. Get back under car with a large screwdriver or crowbar, and just try to move things around, like engine mounts, transmission crossmember, exhaust pipes and so forth.

Also grab ahold of front of propeller shaft, just behind the U-joint and feel for up/down and side to side play. A small bit (almost noticeable) is to be expected. Anything more is not normal.
Then go to rear of propeller shaft in front of the U-joint and try the same thing. Also try to push shaft fore/aft (front to rear). There should not be any fore/aft movement. If there is then the big yoke nut is loose or you have a wiped out differential pinion shaft bearing. If anything more than minor up/down or side to side play is not normal (U-joint or pinion bearings).

If still nothing, then it gets a bit trickier for diagnosing solo. Get a decent camera (one that if damaged is not going to cause a hardship) and some lights. Mount camera and lights under car in rooming areas (propeller shaft joints and transmission mount areas first, then spread outwards). Then try to duplicate the noise(s) with camera on. In most cases the source can be identified within 10 minutes.

If no movement is noticed anywhere under car that is related to noises, then the problem is internal transmission – and in that case, I wouldn’t be concerned unless noises change or get louder. Some transmissions have gear train play that each one is within specs but adds up to a bit of added up play. On most cases it is just not worth fixing. If problem gets worse – then that is a different problem.
BudW

 

[Bruceynz]

Hi Bud,

Yes I can't find one in 27 spline

Whats this one

DANA TRAC LOK POSI 8.25" 27 Spline MOPAR Chrysler 75101X Differential Carrier | eBay

 

[Bruceynz]

Ok when driving if you need to take your foot of the gas a little before it changes into top, that suggests to me I don't have the leaver adjusted right, when you take foot of gas it reduces line pressure and governor over rides spool valve and it changes into top, so I need to loose it off a bit, when you make adjustments are we talking just alter a mm at a time on the leaver, how sensitive is this thing?

 

[BudW]

Both of your links are for the same item (Clutch type) and both will fit your application, just fine.


The one nice thing about linkage systems is sense they either use 5/16” x 18 tread count (or 1/4” x 20 thread count on some) – each ½ turn of the swivel is one/thirty sixth of an inch (or one/fourth of an inch if it uses ¼” threads). Both are finer/smaller than 1mm.

Also, adjusting cables are not as fun because a small bump can equal a large bump too far.

The kickdown cable system is most sensitive just off idle, and setup moves faster then (off idle) than it does at full throttle (where cable/linkage barely moves).
That is why Chrysler has the throttle stud on the carburetor set/start at the 11:30 O’clock position (and ends at the 2:30 O’clock position).

One thing to watch out for. Once you get linkage, err cable, adjusted correctly – check to make sure the cable/linkage does not hamper WOT on the carburetor. It shouldn’t – but depending on how the transmission was set up, it might. If it you cannot get WOT, then you will need to call the transmission manufacture for instructions.

The kickdown is a constant tug-of-war with: throttle pressure (cable) vs. oil pressure vs. spring pressure vs. centrifugal weights (speed). The last two are difficult to adjust. The line pressure is somewhat adjustable – but not that easy.
BudW

 

[Bruceynz]

The clutch ones don't have a very long life though I have read, 20,000miles and your up for a rebuild

I will slacken off the cable a few mm of for you guys 1/8th of an inch and see how we go.

Bud - What one doesn't have clutches? How long do they last? Am I better to buy one for my J body already built and ready to go ad if so who can help me out?

Ideally the best place for me to ship anything from is California where Kiwi Shipping operate then I don't have huge freight bills shifting stuff across the USA, my pockets are not deep quite empty at this point

BTW there is now mounting points for that big block of iron on the tail shaft housing.

 

[BudW]

have heard that as well – but my experience differs, I guess.

I’ve installed many limited slips in these cars over the years (change overs from non-limited slips) and I have yet to see one wore out – even with well over 100k miles on them.
I have seen a few damaged from the pin bolt breaking or backing out (ie: exploded when pin hit a non-moving part) – but not from clutch (or from cone) wear.

If a person did experience worn clutch plates – it is a real simple job to replace. It will take about an hour to change out, roughly.

I have to make a correction – as long as you use the “limited-slip” additive – you should be fine.
If you don’t use the additive, it will chatter as all get out, on turns and that can cause the paper clutches to wear out pretty quick.

My station wagon has the cone style – and it is still way tight.
Sense metal on metal wears faster – I would “think” the cone style would wear out much faster than clutch type (and those, once they are wore out, you toss ‘em).
BudW

 

[Bruceynz]

so what one you thinking is my best option to go for then?
DANA TRAC LOK POSI 8.25" 27 Spline MOPAR Chrysler 75101X Differential Carrier | eBay

or

Dodge Plymouth Mopar 8.25 8 1/4 Auburn Style Sure Grip Posi 3.55 Gears 27 Spline | eBay

or

Mopar Performance Sure-Grip Differential Steel 4529273 Chrysler 8.25" 27 Spline | eBay


I am thinking that Dana one, its new, I have all new bearings already and I just reuse my ring and pinion gears??

 

[BudW]

The first one is Disk type. I rate it an 8.5 (out of 10).

The second one is the Cone type. I rate it (new) a 6.5 (out of 10).
This one is used (nothing wrong with that) and has 3:55 gears – so if considering changing your gear ratio – this would make that job a breeze.
The ring gear was made on Sept. 11, 199_ (can’t read the final two digits).
If not interested in the 3.55 gear set, then I would pass and go for the clutch type.

The third one is a re-boxed – but identical version of the first one.
BudW