Charlene's Hitting The Road...

Jonnyuma

Well-Known Member
Joined
Nov 6, 2011
Messages
342
Reaction score
81
Location
A Dirty Little Town in NW Oregon
In August I'll be taking my 79 Lebaron on its first road trip. Only about 300 mi, but still far enough that I need to get some prepping done since we don't know each other all that well yet.

Fluid changes are imminent, I'm figuring temps at 90° or better so what engine and gear oil would you recommend for the 318 and 7.25" rear? That's really my MAIN question to you guys. I've always been too chicken-sh*t to take one of my old vehicles on that kind of trip... alone. Use a heavier oil? Or stick w good old 40wt?

I reckon a trans filter and fluid change are in order too, as well as packing the wheel bearings.

I read through @SlantSixSullivan's thread about his 1200 mi trip and getting his car prepped... some good advice there.
 

Master M

Well-Known Member
Joined
Nov 22, 2014
Messages
330
Reaction score
116
I use Valvoline 10w30 in the crankcase, and Valvoline 85w-140 in the rear axle on my 1988 5th Ave with 318 and 7.25 axle.
Packing wheel bearings is an excellent idea.
 

Oldiron440

Well-Known Member
Joined
Apr 25, 2017
Messages
3,048
Reaction score
738
Location
Iowa
You asked so here I go, I use synthetic oil, lubricants in everything.....
motor
transmission
rear axle
front wheel bearings
And all lube points.

The benefits far outweigh the negatives In using synthetics.
 

Dr Lebaron

Well-Known Member
Joined
Aug 17, 2011
Messages
2,764
Reaction score
610
Location
Islamic State In Canada
I just took my 79 Lebaron on a 200 mile 6hr tour last Thursday and I'm doing it again on Monday.
If the car is serviced on a regular bases , fluids are OK and not pouring out, what's the problem?

I D/D a 86 F/A and use a 79 Medallion as back up and they'll go 300 miles without a worry.
 

Dr Lebaron

Well-Known Member
Joined
Aug 17, 2011
Messages
2,764
Reaction score
610
Location
Islamic State In Canada
062118lebpt2.jpg
 

Oldiron440

Well-Known Member
Joined
Apr 25, 2017
Messages
3,048
Reaction score
738
Location
Iowa
One thing I have found is that break linings that are bonded need to be replaced every five years or so no matter the miles or condition. I have had more pads and linings falling of lately that looked new.
Probably China parts?
 

Dr Lebaron

Well-Known Member
Joined
Aug 17, 2011
Messages
2,764
Reaction score
610
Location
Islamic State In Canada
You asked so here I go, I use synthetic oil, lubricants in everything.....
motor
transmission
rear axle
front wheel bearings
And all lube points.

The benefits far outweigh the negatives In using synthetics.
I have a BIG NOPE for synthetic oil on a old carbed car or mixing synthetic fluids with others.
Newer EFI, 100% synthetic.

I've had this conversation with guys with WAYYYYYY more engine experience than I can hope for and some big names.
I love my 79, but NO ONE says to use synthetic on it. Not one guy.
From 2 time and 3 time NHRA champions, to old guys who own car empires, Hall of Famers from Sox and Martin.

I use USA Baldwin oil filters.
When you can get ALL the 'Name' filters for free and you use Baldwin instead, there's a reason.
This includes some guy who had the huge Mopar sponsorship and world champion.
Shocked when he gave Mopar oil filters the 'nope' and had data to back it up.
Not just personal preference.
I'll listen to these guys.
 

Oldiron440

Well-Known Member
Joined
Apr 25, 2017
Messages
3,048
Reaction score
738
Location
Iowa
That's funny, the racers , engine builders I'm around today ALL use it. My first hand experience is I've never had a failure with synthetic which is not true with conventional oil and gear lube!
I use it in every thing from lawn mower, rototiller, tractor hydraulic and motor, all the hot rods and my daily driver.
I've used it in older drivers that I've had to repair a few leaks, valve cover and intake manifold but I don't own any thing that isn't worth good oil.

I used it in my two stroke See Doo's also for years with no problems.
 

Oldiron440

Well-Known Member
Joined
Apr 25, 2017
Messages
3,048
Reaction score
738
Location
Iowa
If I had to live with a 7.25 rear axle with it's small fluid capacity the first thing I would do is dump the fluid and fill with synthetic!
 

Dr Lebaron

Well-Known Member
Joined
Aug 17, 2011
Messages
2,764
Reaction score
610
Location
Islamic State In Canada
That's funny, the racers , engine builders I'm around today ALL use it. My first hand experience is I've never had a failure with synthetic which is not true with conventional oil and gear lube!
I use it in every thing from lawn mower, rototiller, tractor hydraulic and motor, all the hot rods and my daily driver.
I've used it in older drivers that I've had to repair a few leaks, valve cover and intake manifold but I don't own any thing that isn't worth good oil.

I used it in my two stroke See Doo's also for years with no problems.
I'm talking carbed unleaded motors mainly /6 and 318.
I'll go with my guys.

Not one said go for it.
I only put 1000 miles or so on the 79 and change the oil the day I store it so fresh oil sitting all winter has no contaminants.
Not getting any synthetic benefits with oil change intervals like that.

All new engines in CrapCar and NHRA are EFI., so different story.
 
Last edited:

SlantSixSullivan

Well-Known Member
Joined
Nov 21, 2016
Messages
155
Reaction score
27
Location
East Liverpool, OH
I read through @SlantSixSullivan's thread about his 1200 mi trip and getting his car prepped... some good advice there.[/QUOTE]

Glad you found some of those answers helpful. When I took my Diplomat that far, I did take spare parts with me. Ballast resistor, voltage regulator, belts, hoses, extra coolant, fuel line, coolant hose.. I even brought an alternator, roll of brake line, assortment of brake fittings and my flaring kit. I was NOT going to call a tow truck for something I could fix on the road. Tune up, new fluids, good tires (plus a spare/jack) and you'll be good to go 300miles.
 

SlantSixSullivan

Well-Known Member
Joined
Nov 21, 2016
Messages
155
Reaction score
27
Location
East Liverpool, OH
I now drive that Dippy 70+ miles every day, to and from work. Sometimes more than that, and I'm comfortably cruising at 80mph most of the way
 

BudW

Moderator
Staff member
Joined
Mar 4, 2012
Messages
5,121
Reaction score
1,485
Location
Oklahoma City
Engine oil – you can’t go wrong with 10w30. 10w40 and 15w40 will also work. The thinner the oil – the better fuel mileage you will get – but you don’t want to get too thin.
For a stock vehicle and original engine, I don’t see a need to go with expensive synthetic engine oil – unless the price is right (in my opinion).
If car was fuel injected, is being used for racing and/or if you had a lot of money tied up in the engine, then I will have a huge difference on my answer (synthetic)

For my ’77 Volare and ’86 Fifth Ave, I have a harder time trying to keep engine oil inside of the engine (and making sure both are topped off), than to worry about it being synthetic.


Gear lube is something that gets no attention. There is only 2.5 pints of gear lube in a 7¼” differential – so a little leak can cause a big problem, quick. Using synthetic is a very good idea, there,

When checking gear lube level, the level should be ¼” (6.4 mm) below the rubber plug. I recommend replacing the rubber plug because your original one will be rock hard and will have shrunk some. Most part stores will have replacement plugs in the “Help” isle. Dorman # 65293 if you can’t find it in help section.
I recommend changing the gear lube every 30k miles (which is about time to perform a front brake job on car, to begin with).

The front wheel bearings are to be re-packed every 30k miles. If you do that, it will be rare to have a wheel bearing problem.

I rotate driving my ’77 Volare wagon, ’86 Fifth Ave and my ’86 Dodge diesel pickup every day.
BudW
 

M_Body_Coupe

Well-Known Member
Joined
Aug 19, 2013
Messages
621
Reaction score
293
Location
Windsor, ON, Canada
So at the risk of muddying up the waters some more (LOL) I'm curious what you guys think about synthetic gear oil for our Mopar SureGrip differentials (yes, I'm talking the older 8-3/4" stuff, or I suppose even some of the newer 8-1/4" SG equipped carriers)?

Here is why I ask: a couple of weeks ago I finished up the 4.10 Richmond gearset install in my '742 carrier. It needs the SG additivie, which it got. The gear oil I selected was a non-synthetic 85W140. I am nearly 2/3rds through the break-in 500 mile cycle and need to find a final gear oil spec. However, in researching this issue, I found many sources (manfuacturers such as Eaton for example) who specifically do NOT recommend running synthetic with the SG (clutch-type) setups. The idea here being that synthetic messes up the clutch application process.

On the other hand, almost universally, they all recommend synthetic from a gearset (pinion & crown) lubrication perspective, LOL...yeah, damned if you do, damned in you don't!!!

Even though I keep meticulous records of my car builds/maintenance, for some reason I have nothing on the gear oil I put in with the previous 3.91 SG gearset. It came out looking great, the SG never had any issues either, and since I use synthetic with my daily drives I suspect I may have used synthetic in the SG as well...just no way to prove it.

Sooo...what say you?
 

BudW

Moderator
Staff member
Joined
Mar 4, 2012
Messages
5,121
Reaction score
1,485
Location
Oklahoma City
A very good question.

I do know that clutch type limited slip differentials will chatter around turns if no limited slip additive is added. That chattering is removing a good portion of the clutch plate facing each time it does chatter.

On the same note, is the additive counter-acting the synthetic property’s of the lube?

I don’t have an answer.

Additive is not needed for the cone type limited slip (which clutch is metal grinding against metal).


Then there is the Eaton Truetrac differential that doesn’t use clutches and can run normal or synthetic lube. The Truetrac is the limited slip differential I recommend to use – but they do not make it for all differentials, yet (like the ’68-96 8¼” version that FMJ vehicles use is N/A).

Here is what Eaton says about lube: “Lubrication Specifications, Detroit Truetrac® High quality mineral or synthetic gear lubes are required for use in Detroit Truetrac differentials. Regardless of the lube type, always use a GL5 rated lube with the least amount of friction modifier. Mineral
lubes lacking friction modifiers (limited-slip additives) were historically recommended for all Truetrac applications because friction modifiers can slightly reduce the bias ratio (limited-slip aggressiveness) of Truetrac differentials. However, to address the continually increasing power outputs of modern powertrains, many vehicle manufacturers have switched to synthetic lubricants as a counter measure for increased axle temperatures and prolonged service
intervals. In general, consult the vehicle owner's manual for the manufacturer's recommendations for lubrication type, weight and fill volume. This will ensure lube compatibility with the seal materials and bearings used in the axle. Eaton Performance technical support is available for any concerns in lube selection.”

BudW
 

Oldiron440

Well-Known Member
Joined
Apr 25, 2017
Messages
3,048
Reaction score
738
Location
Iowa
500 mile break in, I've had 8 3/4 gear sets last 125 passes, about 60 miles and there missing teeth. A switch to synthetic and I pull them at 400 passes.
I use 4.88 pro gears...
 

Poly

Well-Known Member
Joined
Jun 15, 2018
Messages
137
Reaction score
21
Location
USA
Ours is a Sure Grip. When changing the differential lube we used what we had on hand. Royal Purple 75-140. Max Gear or something close. There were no noises or problems before or after. Richmond gears, I have no idea.
 
Back
Top