4" lift and shock upgrade Bigfoot 19'

[Jared L]

Alright, been on here for more than 4 years, about time for my first post.


I have had my 84 Bigfoot 19 Gaucho for over 2 years now. It is a great trailer and rides extremely well but the ground clearance was not acceptable. On several occasions I have had to stop to put rocks and logs under the wheels to get through even the most minor washout on BC logging roads. I like to frequent the more remote BC rec camp sites. The trailer was also not handling the washboard on the logging roads as well as I liked. Carbonated beverages in the trailer could not be opened for a while after arriving at camp.


I decided to do both improvements at once for time and cost savings. People have done the straight axle swap and added shocks but I could not find good documentation on it so i decided to share my experience/learning. I am in no way ensuring this will work for your trailer, if you choose to copy my setup in any way it is your responsibility to verify that it will be safe for your application. Proceed at own risk.


OK, got that out of the way. First off, here is the trailer before modification (yes it needs a bath).







First step was to order some straight axles to replace the 4” drop axles. I was shocked at how affordable the axles were from our local mfg in Calgary so as long as I swapped over the brakes and hubs. Little did I know what surprises were coming (not the mfg's fault on the axles).


Next was to figure out how to get shocks on it now that Monroe no longer makes their retrofit kit for trailers and the only place that still had them in stock wanted more than $200 shipped for 2 kits not including the shocks. I can figure this out myself.


From experience on other projects tackling the hardest challenges first seemed wise -Lower mounts. After measurements and research I discovered that 60's era jeeps had the same width front springs as my trailer with a shock mount on the u-bolt plate (no sway bar mount). After receiving them I discovered that the holes on one of the plates was spaced further apart due to the differential on the jeep axle. Measured my axles and decided slotting the holes would solve this. Used a round file and it only took about 10 minutes. These plates use a 7/16” dia u-bolt which is smaller than the standard 1/2” on a 3500 axle which this trailer has, but were de-rated from the factory. Since my trailer is 2600 dry, I figured i need nowhere near the 7000 lb rating that the two axles would be rated for and would be fine.





Upper mounts were not as simple as I thought. I originally wanted to get 5/8” shoulder bolts for the increased strength as they were going to be loaded outboard of the frame walls, however they would have been much more expensive and I would have to have very accurate holes machined in the frame with threads in one side. I would have to rent a mag drill to keep them square and I know shocks do not require anything even near that level of accuracy so I went with a cruder, less expensive solution. I picked up some 1/2”dia 5” bolts with a box of washers. I still needed a spacer to bring the dia from 1/2” to 5/8” for the ID of the shock and after a lot of searching, I picked up a bronze bushing (1” to 1-1/4” long 1/2” ID and 5/8” OD). The part is actually a bearing from an electric motor. But you can pick these up from industrial suppliers. The Monroe trailer shocks came with some spacers but I had to add about 3-4 washers to gain enough clearance to from the frame. Another benefit to going down to 1/2” is that most standard drills can take up to 1/2” drill bits and the hole in the frame would not be as large. I am going to keep an eye on the bolts as they are not hardened and might fail over time.


I used the Monroe trailer shocks (there are several lengths but almost every trailer on this site would require the shortest. Online shopping saved a ton of money on these (especially in Canada).




Getting the old axles off was not as hard as I thought, even on a 29 year old trailer. Don't bother trying to unbolt the u-bolts, cut them or torch them off. You can not re-use them either as they are designed to deform under torquing and re-use could result in failure. Unless you want to remove the brakes before the axle, you will need to drop the spring by removing one of the spring boats.

[Jared L]

The brakes proved to be the most challenging part of the job. When the axles were manufactured, they did not machine enough off of the brake mounting face of the axle to get a socket on the nuts. 29 years of rust proved to be a large challenge too. I used a hole saw to machine enough off of the face to get a socket on the nuts. Some of the studs came loose so I needed to replace them with bolts (very cheap at the local Calgary mfg). When I tried this on the second axle, the hole saw was getting shredded and hardly touching the metal. For some reason this axle had a much higher hardness. I could have used a diamond hole saw, but at this point i was running out of time so I picked up some new brake assemblies for the second axle.








Putting axles back on was easy. The bolts through the spring stack will keep the alignment with the axle, so unless there was an alignment problem before the swap, everything should be fine.








The shocks mounted very quickly. Just had to make sure that the shocks would not over extend and with a double axle the negative travel can be more than it appears. Drilling the frame took a little while but with some cutting fluid went smoothly. The shock angle on the rear shocks had to be steepened a bit due to the shower drain interfering with the mounting. Loctite was used on the shock mounts to keep the nuts from backing off.

[Jared L]

Here is the trailer after the modifications and a good cleaning.







Here is why we all do this.






Happy to give back, you have provided so much good information to me.


JL

[Brian B-P]

Good work!

But a lot of work... I'm glad that the Monroe kit was still available for me, and that I did not need to change the axle beam. Also, although my axle was just as old, the U-bolt nuts came off with real difficulty, so I did't need to cut them.

An alternative to the Jeep plates - which were a brilliant solution - is the Dexter kit, which uses simple plates with a bent extension, and stud-ended shocks to go through a simple hole in them. The Dexter kit also includes the shocks, and a weld-on top mount. I didn't want the welding. My non-moulded fifth-wheel has the Dexter kit; it seems to be the common choice for factory-installed shocks on leaf-spring beam axles.

[Brian B-P]

One question:
Why put the shocks on the inboard side of the frame rails? Is there not enough clearance on the outboard side?

[cpaharley2008]

I'm curious as to why not replace the springs also or in lieu of the shock upgrade? That may have resulted in the same improvement. Those springs look really old.

[Brian B-P]

Originally Posted by cpaharley2008

I'm curious as to why not replace the springs also or in lieu of the shock upgrade? That may have resulted in the same improvement. Those springs look really old.

They're old, but they still have lots of arch. If the springs have the same 3500 lb/pair rating as the axles, they're very lightly loaded and could last a very long time. As I recall, the Bigfoot 19' we considered buying had 2500 pound axle ratings, which would be more reasonable (and ride better). With only three leaves in the pack, I suspect these are 2500 lb springs; that wouldn't explain the long life, but does help explain a lack of inter-leaf friction damping and goes with Jared's comment about factory de-rating.

Even if the springs need replacement, new springs would not make the kind of height difference that the straight-beam conversion does... but I realize Jim is asking about the need for shocks, not the lift.

Shocks do something fundamentally different from springs. They add damping which smooths the ride, in a way that even the most perfect steel spring cannot do. The only damping in a leaf spring comes from inter-leaf friction; it will never be as strong as a proper shock, and frictional dampong is poor compared to the hydraulic damping of a shock.

[MC1]

Really nice job. It did look too low in the original pic.

[Thomas G.]

Great work. It's amazing how a few rusty fasteners can double the labor on any job.

[jwcolby54]

Did you need to adjust the tow ball height? It seems that the angle would be different after this mod (angled down more without adjustment).

BTW, thanks for sharing. I am looking at this mod, or jacking my trailer up 4 inches or so. I have absolutely no mechanical aptitude however so ...

Am I correct that these eggs do not usually have shocks as a standard item?

[Thomas G.]

Originally Posted by jwcolby54

.......Am I correct that these eggs do not usually have shocks as a standard item?

Shocks are rare and usually added by an owner as opposed to the factory.

[jwcolby54]

My scamp 16 is a 2009, so "almost new". I'm hoping that there will be little corrosion yet and thus easier to mod if I get to it immediately. I would like to lift it a few inches, install shocks, and if possible get bigger tires on it. 13" tires just seems undersized to me, and at least in the scooter world, they wear much faster than the larger tires.

So what is involved in a "lift"? Is it the shape of the axle? I.e. swap the axle out for a new one with a different shape?

Am I just nuts to even be thinking about this?

[Brian B-P]

Originally Posted by jwcolby54

My scamp 16 ...
So what is involved in a "lift"? Is it the shape of the axle? I.e. swap the axle out for a new one with a different shape?

Assuming it still has the original type of suspension, a Scamp uses a completely different suspension type from a Bigfoot 19, so what is involved in a lift is entirely different.

For the Bigfoot, yes, the axle beam goes from a shape which drops down from hub to beam at each end, to one which is just straight.

The Scamp can be lifted, too - maybe someone can point to a good choice among the many existing discussions - but it is unrelated to what Jared is showing us. Similarly, shocks can be added to the Scamp - and again maybe someone can point to a good existing discussion - but again it is not done the it is done for the Bigfoot axle. There's one thing in common: due to the discontinuation of the Monroe kits, adding shocks is an exercise in custom fabrication.

[Brian B-P]

Originally Posted by MC1

It did look too low in the original pic.

Yes, it looked low, but I think that's mostly the visual effect of the fender skirts, and partially the fact that the intended height was lower than is currently fashionable. For normal road use, there's lots of clearance visible between the body and the road.

[Jared L]

Thanks for the compliments!


Brian - I did look at the Dexter kit but did not want to have to take it in for welding, it is more expensive and the shock selection for that style of mount is limited. I mounted the shocks on the inside due to space constraints on the outboard side. While they would fit with the trailer static, they did not have sufficient clearance once the axle goes through its range of movement. They are also protected by having them on the inside.


Jim – springs are fine, might be sagging a wee bit ~1/2”, but for 29 years old, they are in great shape. Don't forget trailers used to have less ground clearance and the Bigfoot’s fibreglass shell extends well below the frame in many areas. I think my trailer was babied/barely used by the previous owners, though I believe they had not waxed it in more than a decade. I can now drag myself from one end underneath the trailer to the other with out any jacking, and I am no small guy either. It has more clearance than my 4runner now!


Brian – exactly what I though about the spring capacity, The axle, bearings and brakes are still rated at 3500. Just had a uh-oh moment. I did not tell Standens to de-rate the axle alignment for the lower weight. ( I might have uneven wear on the tires - though the sidewalls will crack and split before the tires tread is gone.


Tom – rusty fasteners at a minimum tripled the work, more likely 4 times. If everything was brand new, I could probably do it in a day.


John – I raised the ball height about 2”. it now rides with the front slight low as opposed to slightly high before the lift. I had to keep the ball higher pre-lift due to a really bad exit from my driveway. No issues now. Shocks are very rare from the factory. I mainly added them because of the washboard on logging roads and the fact that I go off-road prevented the addition of weight distribution and sway control. I have a very good mechanical aptitude and rusted fasteners were my largest challenge. You need to be confident in using a torque wrench, and have access to one. Having inspected and repacked your bearings would go a long way as well. Watch some of the videos online and if that scares you; bribe, beg or blackmail for some help – any qualified auto mechanic could get you through the hard parts. As Brian mentions the process for a torsion axle lift is different though.


Perhaps someone can chime in on torsion axle lifts?

[LeonardS]

So...the question remains: How's the beer and soda like the new ride? :-0

Still have to wait to enjoy the carbonated beverages?

[Jared L]

I still don't know how well the BEvERageS fares with the shocks. I was cramming to get this done for my parents visit (they steal my trailer and truck to go up into the mountains every year, seniors are the new teenagers!) at least I got to visit them while Calgary got swamped. Interesting story: I left early in the morning of the day the floods began. We had no clue about the extent of flooding till we got back four days after the evacuations. I remember the news radio saying that there were no worries of flooding in Calgary as i left radio coverage on my escape to the mountains. I'm a little late getting this posted as i had been helping a friend out who was 6 feet under during the floods and getting the rest of the visit sorted out. Fortunately I was high and dry through it all.

[jwcolby54]

What do you think of the shocks after having them for a while

[Jared L]

Just got back from a 900 km trip up to the Crows nest pass and to White Swan with a good 80km of rough logging roads. The trailer handles washboard better than my 4runner, but high speed potholes are still a little rough. The BEvERege test was very positive, though a little foamy. What surprised my was the paved road handing. No bouncing no sway and very stable cornering at speed. One very happy camper.

[MC1]

Sounds good. Improvements are a great thing.

With the leafs and good shocks you have probably optimized your Bigfoot's behavior.

Wondering if any anyone has installed torsion axles on a bigfoot. Not cheap but the ride would be creme de creme.