Towing with My burb

[RussTburb]

I recently took the maiden voyage with my Burb pulling our new Travel trailer. It was a great trip except for the traveling part. The old girl just didn't seam to have it in her to pull the trailer. Here are the specs: 150 k miles on stock 402/TH400 2wd, coil sprung rear. Not sure on the gear ratio but I think its like 3.73 or 3.90, putts down the freeway at 60mph turning about 2200-2500 RPMs (This is not towing). I've put in a HEI dizzy, (NOT set the advance curve yet), and I need to regap the plugs (Set to .035 not .045). Overhauled the Q-jet and played around with metering rods, till I got a good "Redneck Dyno" (Power brake in my driveway!) The trailer is an Aerolite 26qs, weighing in at a respectable 4752 lbs empty, and probably close to 7k lbs loaded with water and gear and such. It is supposedly a "HALF TON TOWABLE TRAILER". Power, or Lack there of, was a bit of a problem, definitely not what I excepted from a BBC. The big problem is that it seamed to "push" all over the road and the suspension felt "Loose". I am using 10,000 lb Load levelers with out the sway bar. I'm Researching new springs and bushings for the Burb. Does any one else tow with these things? What should I except? I figured the "Big Blue Beast" would handle it like it wasn't even there, but boy, was I wrong! My wife was WHITE KNUKLIN it in the passenger seat! Any suggestions would be appreciated. Yes I am thinking of baggin' it just not slammin' it!

[RussTburb]

Here are some pics of the Trailer, Its pretty sweet! OH and the BURB!

[Longhorn Man]

the gear should be a 3.54 in a dana rear axle if it is all original.
150K on the engine is quite a lot if it's never been rebuilt. The more I hear/read about these older big blocks, the less I am impressed with them.
I've personally never towed anything in a coil spring truck and thought it was doing a good job... more like what you describe. new bushings in the trailing arms and panhard bar would probably do wonders... poly instead of rubber since you are asking a lot out of it. (less 'squirm')
Take a good look at your rear tires too, and I recomend inflating them to max pressure.

[IAFF2407]

go with a higher gear in the rear, min. 3.73, and maybe check the Q-jet model #, cross reference with;

http://www.cliffshighperformance.com...carb_ID_2.html

your carb could be from CA (emissions) and high altitude. I don't know if emmissions comes into play with yours, but the Q-jet has smaller jets to get past CA. emissions which in turn lowers the HP. I had mine (which was both CA. & high alt.) sent to Jet performance for a rebuild. They increase the jets by 3 sizes.

I haven't broke my motor in yet to pull a trailer, I'll let you know how the Caddy does.

Al.

[RussTburb]

Thanks guys,
Longhorn, You saying that coil sprung don't tow good? (pardon the ZOOLANDER) rear tires fully aired BTW. Any one ever convert coils to leaf?

Al- thanks I'll check those numbers, I didn't mention mine has that goofy air pump thingy on it, and yes that is the technical name! I was thinking about changing gears but it runs so nicely when your not towing, just goes down the freeway, My kid has a C-20 leaf sprung with 4.10 or 4.11 and it is just wound out at 60mph. 3.73 might be a happy medium.

[RussTburb]

OK, Carb #7042218 704= 70-75, 2=last digit of model year (72-original), 2=federal a 4 or 5 denotes CA, 1=Chevrolet, 8=trans option maybe, sometimes even=auto, odd=manual, not always true!

Hey that was cool! Fun and informative. I have I think at last count 6 Q-jets in thee ol' shed. I got lots of numbers, and was thinking about having one of the throttle shafts re-bushed. The one on the truck does not always want to come all the way down to idle.
Here is a cool link to a car craft article that helped with my carb rebuild.
http://www.carcraft.com/howto/57178/photo_05.html

[Big Block]

Originally Posted by Longhorn Man

the gear should be a 3.54 in a dana rear axle if it is all original.
150K on the engine is quite a lot if it's never been rebuilt. The more I hear/read about these older big blocks, the less I am impressed with them.
I've personally never towed anything in a coil spring truck and thought it was doing a good job... more like what you describe. new bushings in the trailing arms and panhard bar would probably do wonders... poly instead of rubber since you are asking a lot out of it. (less 'squirm')
Take a good look at your rear tires too, and I recomend inflating them to max pressure.

I owner a 1972 3/4 ton sub a few years ago. It was all over the road. Replaced The trailing arm bushings and panhard bar made all the difference in the world. Mine hade a 4:56 dana rear end. It was 402/400 and it got 7-9 mpg at 70 mph. It would pull anything I couldn't stand the gas mileage.

[MrBeast]

To help keep your burb under control, I think the best place you can start is with the supension.

What I would seriously look at is bagging it, and instead of using a manual ride height control, use a semi style leveling valve, well not one but 4 of em, if you put one on each corner where 1 valve controls 1 bag, it will actually act as a sway bar, and it will work automatically to keep your ride height where you want it.

The next thing to consider is your rear end, a 3.54 ratio is ok if you are only going to be doing towing in flat land running a direct drive tranny, But seeing as how you live in the Rockies, I would seriously consider a NV4500 conversion. As well as swapping in a 14 bolt with a posi and 3.73's

The advantage of this is, you get an overdriven transmission that will help your millage, it is robust and dependable, and the best thing is, it has a stout granny low that will help lug the trailer around when you need to.

As far as your 402 goes, it just isn't a hay maker of a motor. You do however have a big block burb, that means transplanting a larger big block in will be much easier. I would seriously consider trying to find a Vortec 8100 or a 7400 454. You get the EFI that way with the big block power, I have had 2 of the Vortec 7400's great engines. I wouldn't hesitate to go with one again.

In your shoes I would seriously consider looking around for a late 90's truck that has the 5 speed manual and Vortec 454, this way you would get the 14 bolt, 454, tranny and everything you need in one shot. I have seen them for as low as 3 grand in decent condition, where the body was junkable but the drive train was good.

Also it is hard to tell but are you running an equalizer hitch? That will make all the difference in the world.

[IAFF2407]

I put a 14 bolt 3.21 rears in mine, and a gear vendors which gives me overdrive ( $3k). For the caddy this gives me great gas mileage, and for the 3 week holiday every year pulling the trailer I will put in the 3.73 gears.

I have installed RE7 bags and Rancho 9000 shocks on the rear, I'm not completely sold on this setup yet, but I'll pass judgement when I've trailered

yours is a 3/4 t, the rear should be plenty strong, I only changed to the 14 bolt for the bigger brakes and easier to get parts (drums go for $225 up here)

[mr48chev]

I'd think that the condition the engine is in and or the state of tune it is in have just about everything to do with the power or lack of power.

When they were new those burbs were bought to tow trailers that size but probably heavier at the time. One thing I would seriously suggest if you don't have it is an equalizer hitch. It is probably the best investment in helping control the trailer and will take some of the load off the rear suspension of the truck. I would do that before getting involved with springs, shocks or airbags.

Do make sure that everything in the burbs suspension and steering is in top rate shape and that the wheel alignment is correct. Any looseness will be exaggerated by the load on the back.

[Longhorn Man]

I was only meaning that the few coil spring trucks that I towed with sucked... I've heard people on here say they are fine though... so I can only assume that the 3 trucks I towed with were ragged and worn out... which i KNOW for a fact 2 of them were. The third one seemed real nice, but was probably tired underneath.

[MrBeast]

Originally Posted by Longhorn Man

I was only meaning that the few coil spring trucks that I towed with sucked... I've heard people on here say they are fine though... so I can only assume that the 3 trucks I towed with were ragged and worn out... which i KNOW for a fact 2 of them were. The third one seemed real nice, but was probably tired underneath.

A good set of springs and shocks make all the difference in the world. What you have to consider here is that when you are towing a trailer, much of it is transfered to the truck, IE the tounge weight. So the truck (or in this case burban) has a much greater force acting upon the springs, if you have a set of 40 year old wore out 1/2 ton springs, sure they are going to send you for a wild ride, especially if you have a heavy trailer.

[Longhorn Man]

I would think the bushings would be more important here. (not to say you are wrong) The bushings help keep it all in line, springs and shocks would just make it bounce or bottom out. The sway would be more in the bhishings, esp with the long arms these rigs have.

[MrBeast]

Originally Posted by Longhorn Man

I would think the bushings would be more important here. (not to say you are wrong) The bushings help keep it all in line, springs and shocks would just make it bounce or bottom out. The swaw would be mor ein the bhishings, esp with the long arms these rigs have.

Well you are actually very right, if the bushings cant keep everything in line, well then the springs and shocks cant do their job. It is all connected, so we can both be right on this one, and I wont have to force you to eat any eggs.

[RussTburb]

Great info here! Thanks!
I am using a stabilizer hitch. Its a 10,000 lb job, but I might need to play around with setting that up. It does feel like the rear end is moving all around but also a bit like worn shocks. I had them off and gave 'em the old squeeze test and they felt good, but who knows! I am thinking of baggin it and since I work on Transit Busses for a living I think I might be able to rig up the levelers like you were suggesting. The Burb is due for thourough going over/ rebuild. I might get started on it an call it the "Rolling Resto". look for that thread! The other plan is to pull it off the road and do the whole Frame off thing, but I'm really worried about the "don't need it don't fix it" thing in my head and the fact that I really have a bad track record with finishing major projects. But if I do go that route it means a new/used Duramax in my very near future! I think that would look good in my signature! Thanks again and keep it coming!
Dennis

[mr48chev]

How much tension do you put on the bars on the hitch?

In the past I have found that you have to play with it and usually it takes a bit more than one originally thought it would to make things work just right.

[RussTburb]

Well thats just it. I have had to use a a lot, and the RV guys at the dealership showed me how to do it with a little. My saddles on the tounge are still very new so the pivots barely move. The guy said to lower it down on ball with the jack, then down to where you think your truck should sit with all the weight on it but don't put the jack all the way up. Then you find the link you want and hook it on the pivot and it should not take very much to cam it over. Then raise the jack all the way up. I've done it that way and the other way, I've tried different links and it still seems to "push and bounce" all over. Its not horrible just not as good as I want it and my wife is not comfortable. AND IF MOMMA AINT HAPPY....AINT NO ONE HAPPY!!!

[MrBeast]

I would say you need bushings in your rear, you also have to remember, your rear end has a panhard bar, if the bushings in that are worn, whoah nelly it can make for a wild ride.

[RussTburb]

I have quote request out to a couple of businesses already, waiting to hear back, gotten prices from another web sites catalog for springs. I haven't been able to find the Neoprene Bushings or the pan hard bushings, Do you replace it as a unit, like a tie rod end? I'M NOT starting a WTB thread, here just wondering if anyone could suggest and approved vendor.

[MrBeast]

Originally Posted by RussTburb

I have quote request out to a couple of businesses already, waiting to hear back, gotten prices from another web sites catalog for springs. I haven't been able to find the Neoprene Bushings or the pan hard bushings, Do you replace it as a unit, like a tie rod end? I'M NOT starting a WTB thread, here just wondering if anyone could suggest and approved vendor.

I have had good luck with energy suspenions products, you can get them through Summit Racing I believe. They are Poly though. If you go that route, make sure you grease them.

[RussTburb]

Thanks, I ment Poly not Neoprene. Some time my fingers move faster then my brain. Best to grease the poly ones before install?

[MrBeast]

Originally Posted by RussTburb

Thanks, I ment Poly not Neoprene. Some time my fingers move faster then my brain. Best to grease the poly ones before install?

Ha ha, I know how it goes, what I meant to say was that if you put in poly bushings, make sure you set them up so as that they are greasable, otherwise man will they squeak. it is a pretty simple process, you just have to drill and tap a hole, and put in a zerk, clean up any shavings before assembeling.

[prairewolf]

I am only going to be critical of cheap, off brand tires to the point of trying to be helpful,...... cheap,off brand tires should not be on tow rigs, regardless of tread depth or what the white lettering says. '' There is a Lot riding on your tires '' .

everything I just said is a heads up for me as well. ..... I plan to tow with mine a lot too.

life is good,kent

[MrBeast]

Originally Posted by prairewolf

I am only going to be critical of cheap, off brand tires to the point of trying to be helpful,...... cheap,off brand tires should not be on tow rigs, regardless of tread depth or what the white lettering says. '' There is a Lot riding on your tires '' .

everything I just said is a heads up for me as well. ..... I plan to tow with mine a lot too.

life is good,kent

+1 on a tow rid id be running michelin's and on a 4x4 BF goodrich mud terrains.

[vectorit]

As for your motor... With all the mileage you got in it, I would be very suspect of the cam. I have seen many of the early BBC's wear down one or more of the lobes, while the engine runs and sounds good the power is lacking plus a few of your plugs prolly foul more than the others? If you don't have the cash to do a full rebuild, I highly recomend changing out the timing gear set and get a new cam kit. I really like the Comp Cams 268 grind, and you will really see a difference in the low end grunt! There is a bit of a lope, but its only noticeable on those cold morning start ups. Being the year of your rig, you don't have to worry about smog cert violations n all. If you go with a full rebuild, check into getting a semi open chambered head. That heads combustion chamber and cam set I mentioned above is a sweet set up. Just as long as your piston dome isn't so high that your compression ratio goes above 9:1, anything higher than that you will be in trouble with to high of compression and with todays gas that isn't a good thing to do in your situation. As for your transmission, look into getting it set up for towing. Heavier duty bearings and clutches, plus opening up the valve body for better shift points. Plus, don't over look the stall converter RPM range set up. A worthy auto trans builder should set you up right.
After reading your original post, it brought back many memories of growin up doin the camping trips in the burb pullin a trailer. The part about your wife white knucklin it cracked me up, since my mother often did that even when the truck was only a few years old! Since my burb doesn't have AC, and its a 4x4 with a manual transmission that howels like an old yellow school bus. Mix that with 100 plus degree weather, there is gonna be a truck load of not so comfy passengers! Ahh those were the days...